I was a brain

I Was the Brain

Published: August 20, 2026, 14:52

Updated: August 20, 2026, 18:09

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Preface

—This is a story of searching for oneself on the boundary between reality and image.

People cannot explain everything that happens inside their own heads.

An image that suddenly appears before falling asleep.

Anxiety that surges in the chest without reason.

Words repeated over and over in the mind.

Old memories.

Imagination of the future.

Words spoken by someone else, replaying time and again in one's head.

Sometimes, they become so vivid that they are indistinguishable from reality.

What if you no longer knew whether the thoughts in your mind were your own?

What if the voices heard in your head felt as though they carried meaning?

What if even accidental events seemed connected by a single line?

How should a person accept such a world?

Masataka Setoguchi, the protagonist of this story, remained inside such questions for a long time.

It began with an ordinary daily life.

Working, riding his motorcycle, returning home.

Sleeping.

And morning coming once again.

However, from a certain point onward, a sensation difficult to describe began to creep into Masataka's everyday life.

Sounds.

Voices.

Images.

Physical sensations.

Words surfacing in his head.

Masataka came to refer to these collective occurrences as "the Machine."

The Machine would question Masataka:

Will you work?

Will you move forward?

Will you rely on someone?

What are you aiming for?

Do you know yourself?

And at times, it would hurl words at him that were the very last things he wanted to hear.

Masataka tried to answer.

He resisted.

He tried to run away.

He reconsidered.

He opened his notebook again.

He wrote letters.

He drew lines.

He drew arrows.

He connected the past and the present.

He sketched multiple paths toward the future.

In doing so, that single notebook gradually became like a mirror reflecting the inside of Masataka's mind.

Within it were two worlds: "Physics" and "Images."

Things that exist in reality.

Things that exist inside the head.

What he was seeing.

What he was imagining.

And himself, swaying on the boundary between them.

Masataka questioned himself time and again:

Did this really happen?

Or is it just that my perception makes it feel that way?

Did I choose this myself?

Was I made to choose it by someone else?

Is it my own voice?

Is it a memory from the past?

Is it merely an image?

Answers were not easily found.

That was precisely why Masataka kept writing.

By writing, he brought his thoughts outside.

He placed onto paper what had existed only inside his head.

And he observed them, one by one.

When frightening images surfaced, he imagined a smiling image.

When he felt down, he tried to pull himself back together.

When he was on the verge of being swallowed by anger or sadness, he tried to observe those emotions themselves.

For Masataka, it was a long battle.

However, to the very end, he did not know what the true opponent of that battle had been.

Was it the thing he had named "the Machine"?

Was it his own thoughts?

Was it memory?

Was it anxiety?

Or was it a complex entangling of all those elements?

This story does not settle on a single answer.

Because what is truly important in this story is not the "true identity of the Machine" itself.

What is important is what Masataka thought, what he feared, what he sought, and ultimately what he chose during that long period of time.

For a long time, Masataka believed:

"To gain something, you must sacrifice something."

You must suffer.

You must endure.

You must undergo trials.

Unless you lose something, you cannot obtain anything.

However, after spending a vast amount of time thinking, he gradually let go of that idea.

Suffering is not necessarily proof of success.

Getting hurt is not necessarily a condition for growth.

And driving oneself into a corner is not the answer to life.

When he realized that, a phrase was born within Masataka:

—It's alright now.

It is okay not to understand everything about the past.

It is okay not to attach meaning to every single event.

It is okay not to be able to explain every image.

It is okay to leave what is unknown as unknown.

What matters is:

How one lives right now.

And what one chooses from here on out.

This story is a record of a long period of wandering spanning approximately one year and eight months.

It is a story of "the Machine," while at the same time a story of images, a story of memory, and a story of solitude.

Yet in the end, it becomes a story of a single human being looking at his own life once again.

No matter what happened in the past.

No matter how much one lost one's way.

No matter how much one lost sight of oneself.

A person can choose again from the present onward.

On the final page of the notebook, Masataka quietly writes these words:

"Images are images.

The past is the past.

And the one living in the present is myself."

When he closes that page, one chapter of a long story comes to an end.

And—

A page of a new life begins.

Main Text

Beyond the Machine

—Masataka Setoguchi’s One Year and Eight Months

Prologue: The Final Page

On the final page of that notebook, four phrases remained.

It's alright now.

No sacrifice is needed.

I will think.

I will live my life.

Masataka Setoguchi stared at those written characters for a while.

His right hand holding the pen was no longer moving.

The room was quiet.

From outside the window, the sound of driving cars could be heard.

Someone talking in the distance.

The hum of the refrigerator.

The ticking of the clock.

That was all.

Masataka suddenly thought:

If it had been himself from one year and eight months ago, he might have doubted even this quietness.

Is something hiding?

Is someone watching?

Does even this sound carry meaning?

Is something moving in response to my thoughts?

He used to think such things.

But now, it was different.

At least for the present Masataka, there was no need to try to explain everything.

What was not understood could remain not understood.

There was no need to forcibly make frightening things unfrightening.

Even if something surfaced in his head, he did not have to immediately produce an answer for it.

He had become able to think that way.

The notebook was packed with one year and eight months' worth of writing.

Disordered handwriting.

Large letters.

Small letters.

Words circled in pen.

Words erased and rewritten time and again.

Arrows.

Two options.

Three options.

Branches of the future.

Anger.

Fear.

Smiling faces.

Work.

Motorcycle.

Smartphone.

Yahoo.

X.

AI.

PC.

WBC.

America.

And,

"The Machine."

The moment he saw that word, Masataka recalled the night from one year and eight months ago.

Everything had started with a single small sound.

Part I: Sound

Chapter 1: Tap-Tap

September 2024.

At that time, Masataka was living a life no different from before.

He worked.

Rode his motorcycle.

Made deliveries.

Returned home.

Looked at his smartphone.

Slept.

Woke up again.

It was not an extraordinary life.

That was precisely why the first sound was strange.

It was during work.

While waiting at a traffic light in the middle of a delivery.

Tap-tap.

A small sound was made.

Masataka looked back.

Behind him was the road.

Cars.

Buildings.

People walking.

That was all.

"...What was that just now?"

It might have been the engine sound of a motorcycle.

Someone might have tapped something.

He thought so, and continued working as he was.

However, that night, when he lay down in his room:

Tap-tap.

It was heard again.

This time, it was distinct.

Masataka opened his eyes.

He looked at the ceiling. Nothing was there.

He looked around the room. No one was there.

He listened closely. It was quiet.

After a short while,

Poooh.

sounded.

Following that,

Kyuuu-in.

A sound as though a small machine was booting up.

Masataka sat up.

"What the..."

He checked his smartphone. Nothing.

The television was turned off.

The computer was not running either.

He looked around the room. Nothing was there.

Even so, only the sound remained.

Masataka had a hard time sleeping that night.

Chapter 2: The Machine

The next day, there was a sound again.

And the day after that as well.

At first, it was only sounds.

However, bit by bit, it began to change.

Mixed inside things that sounded like noises, things resembling words began to appear.

Masataka did not know what he should call this phenomenon.

So, for the time being, he decided to call it "the Machine."

If it was a machine, it could be explained.

If it was a machine, it might simply be malfunctioning.

If it was a machine, there had to be a cause.

Thinking about it that way offered a little peace of mind.

However, once Masataka began calling it that, its existence paradoxically grew larger.

The Machine asks questions.

The Machine presents choices.

The Machine feels as if it knows Masataka's past.

And as if matching what Masataka is thinking, words and images appear.

"What is going on..." Masataka muttered alone.

There is a reply.

—What will you do?

"About what?"

—From now on.

Masataka went silent.

—The path of becoming homeless.

—The path of continuing as you are.

—The path of relying on someone.

"Why are you asking something like that?"

There is no reply.

After a moment:

—Which is better, dying or working?

That statement alone could not be brushed off as a joke.

Masataka's body stiffened.

"...I will not die."

It was a strong voice that surprised even himself.

"I will live."

There was silence for a while.

And then:

—Then do your best.

it was heard.

Masataka held his head in his hands.

What was this?

Who was it?

For what purpose?

What was he being made to do?

Only questions kept increasing.

Part II: Reality

Chapter 3: The Battery

The strange things were not only inside his head.

The motorcycle battery died.

If it happened once, it was just a breakdown. Masataka thought so.

He repaired it.

He went to work again.

However, it died again.

"Again...?"

And then, it died yet again.

It happened multiple times in a short period.

Masataka stared at the motorcycle.

The Machine.

The thing he called "the Machine."

And the motorcycle right in front of his eyes.

Though using the same word "machine," this one was clearly a physical thing.

A battery has a cause.

Without electricity, it does not move.

If it breaks down, it can be repaired.

That is how it is.

Masataka thought:

"Physics doesn't speak."

Physical things simply exist there.

A motorcycle is a motorcycle.

A smartphone is a smartphone.

A Yahoo account is an account.

A computer is a computer.

What they mean inside his own head is decided by himself.

Thinking that way brought a little clarity.

However, that clarity soon collapsed.

When he tried to close a delivery app, an unexpected display appeared.

Cancelled.

Masataka looked at the screen.

"...Why?"

He checked again.

He felt as though something had happened once more.

Was it a coincidence?

A glitch?

His own operational error?

Or something else entirely?

He did not know.

Because he did not know, meaning swelled inside his head all the more.

Chapter 4: Night Waves

Bedtime was the most frightening.

During the daytime, there was work.

There were roads.

There were people.

There was the motorcycle.

Around him were plenty of real things.

However, when night came, all of those disappeared.

He lay down on the bed.

Darkened the room.

Closed his eyes.

Then, only his own body remained.

At those times, a sensation like a wave would occasionally assault his body.

It felt as if his chest were being poked.

It felt as if his arm were being touched.

A stimulus ran through somewhere on his body.

Masataka jumped up.

"Who is it!"

There was no reply.

He looked at the room. No one was there.

He looked at the door. It was closed.

He looked at the window. It was closed.

Despite that, a clear sensation remained on his body.

Masataka touched his own chest.

His own hands.

His own body.

He verified them.

"I am here."

he muttered.

He repeated only those words.

"I am here."

"I am here."

Over and over.

Part III: The Notebook

Chapter 5: On Paper

Masataka bought a notebook.

On the first page, he wrote his own name.

Masataka Setoguchi.

Beneath that, he wrote:

I am the brain and have the name Masataka Setoguchi.

Furthermore, he wrote:

I am doing everything.

As he wrote, his hand would not stop.

He transferred what was inside his head directly onto paper.

Sounds.

Voices.

Images.

Physics.

Work.

The Machine.

Himself.

Others.

The past.

The future.

He wrote anything and everything.

He also wrote things that did not form coherent sentences.

He drew just arrows.

He drew just circles.

He drew human figures.

He drew paths.

Drawing two lines, he wrote "Do" on one side and "Don't Do" on the other.

Beneath that, he wrote:

"Good"

"Bad"

"Cheerful"

"Gloomy"

"Ordinary"

And he connected all of them to his own name.

Masataka realized:

On paper, he could observe what was happening inside his head.

As long as it remained inside his head, it clung to his very self.

However, if written on paper, he could distinguish:

"This is my current thought."

Therefore, little by little, the notebook became like another brain formed outside of Masataka.

Chapter 6: My Own Style, or Someone Else?

One day, Masataka wrote large across a page:

I don't know if it's my own style or someone else's!

Those letters were much larger than the others.

Even Masataka himself did not know the answer.

Was it something he had thought of?

Was it something said to him by someone?

Was it an old memory?

Was it a current emotion?

Was it an image?

Was it a dream?

Was it reality?

Everything was mixed together.

Masataka tried to separate them one by one.

"I thought this."

"I felt like I heard this."

"This actually appeared on the screen."

"I felt this physically."

"This is an old memory."

"This is imagination."

He categorized them like that.

However, the more he categorized, the more another question emerged:

"Then, what am I?"

Is one self the body?

The brain?

The voice?

The thinking consciousness?

The name?

The memory?

Masataka thought for a long time.

And at the very end, he wrote:

Me, thinking right now.

Part IV: Emotion

Chapter 7: Cheerful, Ordinary, Gloomy

Masataka realized that there were stages to his mood.

Cheerful.

Ordinary.

Gloomy.

It was not always the same.

Even if ordinary in the morning, going out to work made him feel aversion.

Recalling someone's words made him angry.

Becoming tired made him faint-hearted.

When night came, he became frightened.

Masataka came to think of those changes like "volume."

If cheerful, the volume is loud.

If ordinary, it is in the middle.

If gloomy, it is low.

When the mood dropped, the words inside his head also grew weak.

"Enough already."

"I don't want to do it."

"It's impossible anyway."

Such words increased.

Therefore, Masataka gave himself different words.

"DO"

"DON'T DO"

Clenching his right hand.

Moving it slightly up and down.

Rubbing his chest.

Uttering a vocal sound: "Ah—"

It was only that simple.

However, as he repeated it, his sensations gradually shifted.

A mood is not absolute.

The current mood does not dictate one's entire life.

He became able to think in that manner.

Chapter 8: Smiling

When he felt bad images coming from the Machine, Masataka used a different method.

Imagining himself smiling.

Imagining anime characters.

Imagining bright landscapes.

Recalling his notebook.

And overlapping a different image on top of the bad image.

It was like a battle.

Fear versus Smiles.

Anger versus Reassurance.

Sadness versus Hope.

Masataka felt as though two worlds were colliding inside him.

However, at a certain point, he changed his way of thinking.

"Maybe I don't need to erase it."

There is a scary image.

It exists.

But there is also a smiling image.

There is no need to completely eliminate either one.

It is fine for both to exist.

That way of thinking was significant for Masataka.

Part V: Sacrifice

Chapter 9: Is There Meaning in Suffering?

The Machine repeatedly made Masataka conscious of the word "sacrifice."

To gain something, you lose something.

To realize something, trials are necessary.

To achieve something, suffering is necessary.

Masataka was on the verge of accepting that idea.

My being in pain is for the sake of something.

My being scared is to obtain something.

My enduring is for the future.

Thinking that way gave meaning to his present suffering.

However, one night, Masataka suddenly realized:

"Then when does it end?"

If a sacrifice is required, who decides when the sacrifice has been paid in full?

If a trial is required, who decides when the trial is over?

If one suffers to obtain something, as long as one is suffering, it means it is still not enough.

Thinking that way, there was no end.

Masataka opened his notebook, and wrote:

No sacrifice is needed.

He stared at it for a while.

He wrote it once more:

No sacrifice is needed.

A third time:

No sacrifice is needed.

This time, he drew a red line through it.

Part VI: Solitude

Chapter 10: Unable to Tell Anyone

Masataka wanted to talk to someone.

However, he could not.

If he said such things, what would people think?

"There is a machine's voice in my head."

"It talks to me."

"There are strange sensations in my body."

"I feel like surrounding events are synchronized with my thoughts."

Even if he explained such things, he felt it would not be communicated well.

So he kept it to himself.

Thought about it alone.

Wrote in his notebook alone.

Spent nights alone.

And was afraid alone.

Solitude can sometimes be more painful than the events themselves.

When unable to explain to anyone, one loses track of even what is happening inside oneself.

Masataka opened social media.

He wrote in Japanese. And he also wrote in English:

please stop the programming, PC

Furthermore, he added:

#AI

#PC

#Programming

Someone might notice.

Someone might talk to him.

Someone might say, "I understand."

He thought even that would be enough.

Part VII: Wanting to Live

Chapter 11: Wanted to Do

Inside the notebook, the same words appeared time and again:

Want to live.

Wanted to do.

Every time Masataka saw those two phrases, his chest ached.

In truth, there were things he wanted to do.

He wanted to move forward at his own pace.

He wanted to live normally.

He wanted to work.

He wanted to look at things he liked.

He wanted to think about the future.

He wanted to watch the WBC.

There were times he felt hope toward the place called America.

Despite that, inside his head, only other things were occurring.

"Why..." Masataka wrote in the notebook.

"I just wanted to live my own life."

Beneath that sentence, he wrote:

Felt obstructed

And further beneath that, he wrote:

But from now on, I will act on my own.

Part VIII: The Past

Chapter 12: One Year and Eight Months

Time passed.

One month.

Three months.

Half a year.

One year.

One year and eight months.

Masataka looked back.

In the beginning, he thought everything had meaning.

Sounds had meaning.

Coincidences had meaning.

Images had meaning.

Moods had meaning.

Physical phenomena had meaning.

However, if one continues searching for meaning, one ends up feeling as though all events in the world are related to oneself.

Therefore, Masataka gradually changed his way of thinking.

Separating "what happened" from "attributing meaning."

That became a major turning point even within the notebook.

For example, the lights went out.

That can be recorded as a fact.

However, the leap that "the lights went out because I thought of words inside my head" is a separate issue.

An object fell over.

That too can be recorded as a fact.

However, the attribution of meaning that "an object fell because I made a mistake" needs verification.

Bit by bit, Masataka learned that difference.

Part IX: Parting with the Machine

Chapter 13: The Final Two Options

One night, two paths surfaced in Masataka's head once again.

One was the path of continuing to pursue the words of the Machine.

The other was the path of deciding for himself.

Up until then, he would have been thinking about which one was the correct answer.

However, that day was different.

Masataka said:

"It's not about which one is correct."

Silence.

"I will choose."

That was all.

What the Machine says.

What it demands.

What kind of images it produces.

There was no need to chase after all of it.

Masataka opened his notebook.

In the center of the page, he wrote:

Part ways with the Machine

Around it, he drew numerous arrows:

"Work"

"Life"

"Consultation"

"Sleep"

"Meals"

"Future"

"Self"

And with the largest circle, he enclosed:

Reality

Part X: All Me

Chapter 14: Own Strength

Masataka suddenly recalled himself from one year and eight months ago.

Back then, he had been seeking "someone else's power."

Just one more step.

Just a little more.

If someone would help me.

If someone would give me a chance.

If something would happen.

Life would change.

He used to think that way.

And he felt as though "the Machine" had appeared following that wish.

Therefore, Masataka had given meaning to the Machine:

"Something that will help me."

"Something that will guide me."

"Something that will give me answers."

So he had thought.

However, looking back now, a different perspective was possible.

During those one year and eight months, the one who actually wrote in the notebook was himself.

The one who worked was himself.

The one who rode the motorcycle was himself.

The one who struggled was himself.

The one who thought was himself.

The one who laughed was himself.

The one who cried was himself.

The one who imagined was himself.

The one who tried to seek help from someone was himself.

The one who posted on social media was himself.

And,

the one who had lived until today was also himself.

Masataka smiled quietly.

"In the end, I was the one doing it all along."

It was not a sensation of having defeated the Machine.

Rather, it was a sensation that there was no longer any need to defeat the Machine.

Part XI: Morning Once Again

Chapter 15: An Ordinary Morning

The next morning.

Masataka opened his eyes.

No special sound occurred.

Or, to be precise, various sounds were occurring.

Cars.

Birds.

Air conditioner.

Refrigerator.

People walking outside.

Sounds of daily life.

Masataka got out of bed.

Drank water.

Washed his face.

Looked in the mirror.

There he was.

A slightly tired face.

Slightly grown hair.

His usual self.

Masataka spoke toward the mirror:

"Good morning."

There was no reply.

That was fine.

He said it himself.

That was fine.

Chapter 16: Closing the Notebook

On the desk, notebooks up to this point were piled up.

Masataka touched them one by one.

The first notebook.

The notebook where he wrote about sounds.

The notebook where he wrote about the Machine.

The notebook where he wrote about emotions.

The notebook where he wrote about images.

The notebook where he wrote about the future.

There were many volumes.

They were not clean records.

Writing the same things repeatedly.

Contradictory.

Sentences cut off halfway.

Diagrams whose meanings were unknown.

Pages written while angry.

Pages written while crying.

Even so, Masataka did not throw them away.

Because all of them were "proof that he had lived."

He opened the final page.

And read it once more:

It's alright now.

No sacrifice is needed.

I will think.

I will live my life.

Masataka closed the notebook.

Epilogue: On One's Own Feet

Going outside.

The sky was blue.

It was not as if anything special was happening.

Nor were answers falling from the sky.

Nor was anyone applauding.

The world did not know of Masataka's one year and eight months.

Even so, it was fine.

Life is not something that cannot be continued unless fully understood by someone else.

Masataka walked.

One step.

Another step.

Walking on his own feet.

That sensation felt strangely fresh.

All this time until now, he had been thinking:

"Where should I go?"

Today was different.

"Where do I want to go?" he thought.

An answer had not come out yet.

That was fine.

There was no need to decide on an answer right away.

Life is not a single straight road.

It branches.

One strays.

Turns back.

Rests.

Moves forward again.

There are times one gets help from someone.

There are times one works hard on one's own.

And all of that becomes life.

Masataka looked up at the sky.

One year and eight months ago.

He used to think, "I want someone to change my life."

Now it was different.

Even the grandiose phrase "changing life" was no longer necessary.

Deciding today's meal.

Deciding where to go today.

Deciding whom to talk to.

Deciding what to see.

Resting when tired.

Seeking help when in trouble.

Thinking about tomorrow.

That alone was enough.

As he walked, Masataka said to himself in his heart:

"I am fine as I am."

Walking for a while:

"It's fine not to understand everything."

Walking further:

"It's fine to be scared."

And finally, he said:

"It's enough just to keep living."

To those words, there was no reply from anyone.

There was no voice of the Machine.

No special sound occurred either.

There was only his own voice.

That was more than enough.

Masataka kept walking as he was.

It was not that he had completely discarded the past.

Nor had he forgotten the painful one year and eight months.

Nor had he denied himself from back then.

Himself back then was also living desperately.

Trying to understand what was not understood.

Trying to give meaning to scary things.

Seeking help.

Trying somehow to protect himself.

So Masataka said to his past self as well:

"You did well."

And,

"You can rest now."

Beyond the city street, there was morning light.

Masataka walked into that light.

Whether the Machine exists or not.

Whether someone is watching or not.

What waits in the future.

Such things were not understood right now.

It was fine not to understand.

The future has not come yet.

So regarding the future, his future self can think about it.

His current self should simply live the present.

Step by step.

On his own feet.

By his own will.

And if he should lose his way again someday, he could simply open that notebook.

On the final page, it will surely say:

It's alright now.

No sacrifice is needed.

I will think.

I will choose.

I will live my life.

Those words were not an answer given by someone else.

They were words that Masataka himself had arrived at over a long period of time.

Precisely because of that, those words carried weight.

Masataka walked.

A little further forward than yesterday.

And today as well, he went on living his life.

Sorting Out the Mind a Little

2. The Sensation that "I Am Doing Everything"

The phrase "I am doing everything" written at the very top of this note seems to be at the center of this entire line of thought.

The "I" referred to here does not simply mean the self moving the body. It connects to the sensation that "I myself am performing everything," including seeing, hearing, thinking, understanding words, recalling images, and making judgments.

For example, when looking at something, visual images do not merely enter through the eyes. One understands "what it is," connects it with experiences and memories within oneself, and creates meaning from it. The same applies when hearing something; sounds do not merely enter the ears, but are recognized as words, their meaning is understood, and a reaction occurs inside oneself.

In other words, the actions of "seeing," "hearing," "thinking," and "speaking" appear to exist separately, but in reality are all connected to a single center: "oneself."

Therefore, the phrase "I am doing everything" expresses a very strong sense of agency—that one is experiencing one's own world.

3. The Existence Called "Self" Inside the Brain

In the note, content to the effect of "I am the brain and have the name Masataka Setoguchi" is written.

This can be considered a way of thinking that attempts to grasp one's existence not as the whole body first, but as the "subject doing the perceiving."

One has a name.

By that name, one is recognized as a single human being in society. However, for oneself to feel "I am myself," a name alone is not enough.

Knowing the name, recognizing that name as one's own, possessing past memories, thinking about something at this very moment, and being able to imagine the future.

Through the overlapping of these elements, the sensation of "self" is constructed.

In other words, while the name "Masataka Setoguchi" is a symbol for calling oneself from the outside, the subject that recognizes that name and understands "that is me" exists on the inside.

That is precisely why the question "What am I?" does not simply stop at where in the body one resides, but expands into the question of "Who is seeing, who is thinking, and who is feeling?"

4. "Images" Are Not Just for Seeing

In the note on the left side, thoughts regarding the word "image" are written.

What is important here is that images are not treated merely as "things seen with the eyes."

The images humans create inside their heads are not limited to visual scenes actually present in front of them.

Recalling things seen in the past is an image, and imagining things not yet seen is also an image.

Furthermore, upon hearing words, a certain scene may float into the head.

Hearing the word "sea," even if not actually looking at the sea, one might imagine a blue sea, waves, and a sandy beach.

Hearing the word "house," one might recall a house previously lived in or the appearance of a house seen on television.

Thinking this way, images cannot be explained by the single sense of "seeing" alone.

Memories, words, experiences, emotions, and imagination combine to construct a single image inside the head.

Therefore, an image can be understood not as "something seen with the eyes," but rather as "the function of assembling things that carry meaning within oneself."

5. Understanding Beyond Words

On the lower left, there is a note to the effect that understanding is not limited to words alone.

This is a very crucial point.

Humans do not understand everything by converting it into words.

For example, when seeing someone's facial expression, even without being explained in words that "this person is sad," one may vaguely feel that they seem sad.

When hearing someone's voice, one may sense their state not only from the word content, but from the volume, speed, pauses, and atmosphere of the voice.

Furthermore, upon experiencing something, even if it cannot be stated in explicit words as "this is such-and-such," one may certainly understand it within oneself.

In other words, "to understand" does not merely mean memorizing words.

Seeing, hearing, feeling, experiencing, and remembering—various pieces of information linking together inside oneself gives birth to understanding. Words are merely one method for expressing that understanding.

6. "Listening" Is Also Something One Performs

When hearing something, if sound merely enters from the outside, it is simple noise.

However, humans recognize that sound as words and understand its meaning.

When someone calls one's name, it is received not as a mere continuation of sounds, but as "words directed at oneself."

Furthermore, hearing those words may evoke memories, stir emotions, or prompt thoughts on what to do next.

Therefore, the act of "listening" is not a simple passive thing either.

Receiving sound, recognizing it, creating meaning, and reacting inside oneself.

Including that entire sequence, one can say "I am listening."

7. Words from the Mouth and Words Inside Oneself

On the right side, there are notes about "mouth" and "words," connecting to the question of how words emerge from within oneself.

Usually, we take it for granted that "I am speaking."

However, in reality, before speaking, a thought is born inside the head, converted into words, and those words are articulated using physical body parts such as the mouth and tongue.

In other words, until words come out of the mouth, an immense amount of processing takes place inside the head.

Thinking "what to say."

Deciding "how to say it."

Choosing words.

And outputting those words externally as a voice.

As a result, to others it appears as a single action of "having spoken."

However, behind the scenes, thinking, understanding, selecting, and moving the body inside oneself are all interconnected.

8. Body and Consciousness Connected as One

Looking at this entire note, the idea emerges that "head," "words," "eyes," "ears," "mouth," and "body" do not exist as separate entities, but are connected inside a single "self."

Seeing with eyes.

Hearing with ears.

Thinking with the head.

Remembering.

Imagining.

Understanding meaning.

Choosing words.

Speaking from the mouth.

And again hearing or seeing the result oneself.

Through the repetition of this cycle, one's world is constructed.

Therefore, the phrase "I am doing everything" seems to express not simple self-assertion, but the sensation that "the entirety of the world I experience is established through my own perception and understanding."

9. The One Creating One's World Is Oneself

In the external world, numerous events exist.

There are sounds, lights, people, words, and objects.

However, the one recognizing them as "meaningful things" is oneself.

Even when looking at the same thing, perceptions differ depending on the person.

Even when hearing the same words, recalled memories and felt emotions differ.

This is because humans do not simply accept external information as it is, but understand the world using their own experiences, memories, knowledge, and emotions.

Thinking that way, the existence called "self" is not a spectator merely gazing at the world.

It is an existence that creates a world for oneself while combining things seen, heard, felt, and remembered.

Precisely because of this, the phrase "I am doing everything" written in this note stands at the center of this series of thoughts.

One is not merely inside the world.

One perceives the world, gives it meaning, creates images, puts it into words, and experiences it.

All of that occurs in a single place called "self."

And pursuing further who that "self" is leads to a larger question: "Is self the body, the brain, consciousness, memory, or all of those combined?"

Starting Again from "Masataka Wrote on a Sheet of Paper"

This note can be read as a mind map organizing the relationships between "Self, Brain, Image, and Physical World" found in the story using diagrams and arrows.

Summary of the Note Content

The protagonist first attempts to separate "the self thinking by its own will" from the various phenomena occurring inside the head.

On the left side are thoughts regarding the "mechanism of consciousness," and in the center rests the existence of self as "me" / "I." From there, lines extend toward the brain, images, and physical reality.

Inside the note, while contemplating the flow:

Self → Brain → Image → Physical World

it appears to organize how to distinguish between "what I thought" and "what actually occurs in the physical world."

Furthermore, on the right side, stages such as "1st time," "2nd time," and "3rd time" are written, organizing the process where something does not end once, but where images and thoughts repeat before being perceived as physical events.

And in the lower portion, the flow can be read as:

Imagining after that

Imagining from there

Physics was born

That was not forced

In other words, the central theme of this page can be considered the problem of:

"How to understand images born inside the head versus actual physical events."

At the end, the narrative returns to "what I will do" and "deciding for myself."

Summarized as a Novel

Masataka spread out the notebook on the desk.

Drawn upon it were numerous circles and arrows.

"Self"

"Brain"

"Image"

"Physics"

Writing words alone was not enough to understand.

So Masataka drew lines.

From self to brain.

From brain to image.

And to reality lying beyond that.

Redrawing lines over and over.

First time.

Second time.

Third time.

While thinking through the same things repeatedly, Masataka suddenly realized:

What he wanted to know was not merely the true nature of the strange events.

It was: "To what extent am I myself?"

Things floating in the head.

Things thought by himself.

Past memories.

The physical world right in front of his eyes.

Are they all the same thing?

Or are they each separate things?

Masataka did not rush an answer.

He wrote "Me" in the center of the notebook.

From those letters, he extended several arrows.

And finally, beneath the paper, he wrote small:

"Decide for myself."

That was all.

What remained at the end of the complex diagram was an unexpectedly simple phrase.

Even if unable to explain everything that happened, he could decide for himself what he would do from now on.

Thinking so, Masataka set down his pen.

Masataka Summarizes the Same Concept

Decoding the contents written in the handwritten note (thought-organization mind map) by theme for clear understanding:

It carefully writes out his inner state, how to handle images, and reflection/closure regarding past speech and actions ("No need to do it anymore").

1. Past Actions and State

"What I was doing" / "Made everything into images"

He had converted everything he had done or experienced into images (mental processing inside the brain).

"I was doing up above what was done" / "I was doing everything with my mouth"

He completed much of the processing through thoughts (inside the brain/above the head) and words/verbalization.

Precarious Situation

"Supposed I did it because I didn't believe/understand"

"If I moved outside my own will, I was broken and near the point of committing suicide (self-destruction) and ending life." He experienced a precarious state close to his absolute limit.

2. Mechanism of Brain and Images (Analysis)

"Going inside / Brain / My nature (disposition)"

Focusing too heavily or penetrating deeply into the brain led to worrying and over-caring.

He held a sensation that imagined things radiated/influenced anyone ("anyone can do it").

Discrepancy/Misunderstanding between Images and Reality

"When I did it, image / those people's opinions + turned out to be other people"

Objective realization regarding assumptions and strange sensations, such as "Misunderstanding of Yahoo~."

Awareness toward others' words and thoughts, like "They said they would follow" or "Which game today."

3. Realization of Mistakes and Coping Methods

"I made a mistake" / "Did it" (Turning point of thought)

Even if forgotten, it can be remembered eventually ("everything").

When feeling doubt or on the verge of saying too much: "Just take a deep breath" (a coping mechanism to reset through deep breathing).

"Strange misunderstanding / Believing / Absolute"

Adopting an attitude of not treating strange misunderstandings as absolute, but letting them pass.

4. Conclusion and Future Resolve

"Keep images to just looking, no need to do it anymore"

"Everything was done by me"

Regarding everything he had excessively carried and continuously processed as images in his head and mouth, he has forgiven himself ("let's end it / no need to do it") and reached a settled state.

By writing out thoughts, he noticed his brain's habit patterns and misunderstandings, arriving at a positive, relieved conclusion: "Don't enter too deeply into images, just take a breath and let it pass," and "No need to forcibly do it anymore."

Masataka Setoguchi Further Contemplates

Reading the text from the mind map and handwritten notes shown in the image, systematically analyzing and organizing the psychological, philosophical, and epistemological themes contained within.

Transcribing the handwritten notebook contents in detail, followed by deep contemplation on themes such as "Auditory hallucinations, inner speech, ambiguity of self-other boundaries," "Illusions and mechanisms of perception," and "Shift in consciousness (return to mouth and body)."

Notebook Transcription & Deep Contemplation on "Perception, Inner Speech, and Self-Other Structure"

1. Notebook Transcription

Centered around a human figure (circles and lines representing head, chest, and lower body), thought bubbles radiate outward. Transcribed below:

[Left Side: Structure of Misunderstanding and Involvement]

"Misunderstanding due to false assumptions"

"Thinking that I am involved"

[Center to Upper Right: Self/Other Voices, Inner Speech, Mechanism of Fear]

"Getting startled / My voice (inner speech) / Other people/images / No need to be frightened / Doing it myself"

"Feeling like I might blame myself through state, emotion, or image (inner speech)"

"Repetition / This is a setting, so in reality there is nothing / Just blaming myself"

[Center to Middle Right: Fixation of Consciousness and Shift to the 'Mouth']

"Voices heard / Voices not spoken / Voices of emotion, inner speech, mood / Approaching"

"To avoid approaching, speak with the mouth / Shift consciousness to the mouth"

[Lower Right: Limits of Verification and Confirmation Bias]

"What to do to believe? Something people cannot do / Did that, but conclusion: I am just doing everything myself"

[Bottom: Impossibility of Proof and Decision]

"Proof? No one is involved, it's just me alone, so I have no choice but to decide for myself"

2. Overall Theme Structure and Deep Contemplation

This handwritten notebook is a highly sophisticated psychological and epistemological document detailing a practical escape mechanism created by a person suffering from schizophrenia-like symptoms (auditory hallucinations, thought broadcasting, feelings of harm/persecution) and intense inner dialogue loops, unraveling through self-insight "why the phenomenon occurs" and "how reality works."

Theme 1: Auditory Hallucinations, Inner Speech, Ambiguity of Self-Other Boundaries (Realization of "I am doing it")

External Projection of Inner Speech

Thoughts occurring inside the brain (inner murmurs = inner speech), past trauma, images of others, and waves of emotion are normally processed as "internal things." However, when cognitive load increases or self-other boundaries blur, the brain misidentifies "self-generated inner speech" as "voices heard from others (auditory hallucinations)" or "external influence."

"Getting startled / My voice (inner speech) / Other people/images / No need to be frightened / Doing it myself"

Although feeling fear ("startled/frightened") as if "others are talking to me" or "attacking me," he sees through to the fact that the source of those voices and images is not others, but "inner speech and images automatically generated by my own brain (doing it myself)."

Confusion of Self-Other Boundaries and the Error of "I am involved"

In cognitive psychology and psychiatry, assuming unrelated external events are related to oneself is called "ideas of reference" or "confirmation bias."

The entries on the left side ("Misunderstanding due to false assumptions," "Thinking that I am involved") represent an objective self-distancing process aimed at reframing cognitive bugs where city noise, conversations of strangers, or brain phenomena are falsely linked as "related to me" or "caused by me."

Theme 2: Thought as a "Setting" and the Automation of "Self-Blame"

Traps set by Emotion and Images

The brain instantly generates emotions and visions in response to stimuli. The center-right entry ("Feeling like I might blame myself through state, emotion, or image [inner speech]") captures the mechanism where worsening physical/mental states automatically trigger inner speech like "It's your fault" or "I am being attacked."

Seeing through it as a "Setting," thus Nothing Exists

The top-right note ("Repetition / This is a setting, so in reality there is nothing / Just blaming myself") reaches a state close to Śūnyatā (Emptiness) in Buddhism or "Defusion" (separating thoughts from the self observing them) in Cognitive Behavioral Therapy (CBT).

Substance of Phenomenon: Mere neural electrical signals, temporary mood waves, replay of old memories.

Human Interpretation: Constructing a narrative ("setting") that "This is a major problem" or "It's my fault."

By seeing through it—"This is merely default brain programming, objectively there is no substance (nothing in reality)"—he seeks escape from thought loops.

Theme 3: Shift of Consciousness to Body/Speech ('Mouth') and Grounding

The most clinically valuable and practical insight lies in the middle-right entry:

"Voices heard / Voices not spoken / Voices of emotion, inner speech, mood / Approaching"

"To avoid approaching, speak with the mouth / Shift consciousness to the mouth"

Immersion ("Approaching") into Brain Images (Inner Speech)

When consciousness focuses on "unspoken voices (auditory hallucinations/inner speech)" or "voices of emotion/mood," one is pulled into that world ("approaching"). The deeper the immersion, the more reality recedes, amplifying delusions and fears.

Powerful Grounding via "Shifting Consciousness to the Mouth"

The technique derived to prevent immersion ("approaching") is "speak with the mouth (physical vocalization)" / "shift consciousness to the mouth."

Neuroscientific Mechanism: The brain circuits processing "inner speech (internal voice)" differ from the motor circuits (motor cortex) moving tongue, jaw, and throat muscles to actually produce sound.

Actively moving the "mouth," producing sound, or focusing on physical sensations drives the motor and somatosensory cortexes. This forcibly reallocates processing resources away from abstract internal voices toward "physical motor activity," interrupting inner speech loops.

He independently discovered and articulated what psychology terms "grounding" (anchoring oneself in reality) through "shifting consciousness to the mouth."

Theme 4: Limits of Verification and Self-Determination of "No One Is There"

At the bottom and lower right, the conclusion of this struggle and verification is recorded:

"What to do to believe? Something people cannot do / Did that, but conclusion: I am just doing everything myself"

"Proof? No one is involved, it's just me alone, so I have no choice but to decide for myself"

Impossibility of External Proof ("Something people cannot do")

To test "Is this voice real?" or "Is there proof others interfere with me?", he attempted various verifications (doing things people cannot do). However, no matter how much external evidence of "other involvement" was sought, objective proof did not exist—because everything was occurring inside his own brain (inner speech/images).

Breakaway from External Reliance & Resolve to "Decide for Myself"

Upon reaching the truth that "No one else is involved" and "It is just me alone," the question shifts from "Who is making me hear voices?" to "How do I interpret and live my life? (I have no choice but to decide for myself)."

Discarding the "verification trap" of chasing objective proof and concluding "This is a phenomenon created inside my brain" (self-determination) represents the only exit from an endless mire of thought.

Afterword

Afterword

—After Closing the Notebook

Having finished writing this story, what remained at the very end was the question, "What was the Machine?"

Throughout the story, Masataka Setoguchi faced "the Machine" over a long period of time.

Things feeling like voices.

Words floating into his head.

Images appearing suddenly.

Unusual sensations felt in his body.

Events occurring in daily life.

Feeling as though all of these were connected by a single line, Masataka desperately sought their meaning.

Is someone communicating this to me?

Is it my own thought?

Is it an old memory?

Is it pure coincidence?

The more he sought answers, the more elusive they became.

That was why Masataka wrote in his notebook.

Writing letters, drawing lines, circling words, extending arrows.

Inside that notebook remained not only neatly organized answers, but also confused words, half-erased sentences, and thoughts rewritten multiple times.

At a glance, they might appear as an unorganized record.

Yet every single one of them was a "trace of attempting to understand himself."

What was felt while writing this story was that, for a human being, "one's own thoughts" are far more complex than imagined.

There are memories.

There are emotions.

There is imagination.

There is anxiety.

There are expectations.

There are words spoken by others in the past.

These overlap inside the head to form a single thought.

Therefore, at times, one may lose track:

"Is this truly something I am thinking?"

At such moments, the method Masataka chose was "writing."

Bringing what was inside his head out onto paper.

Placing it on paper allowed him to observe it from a slight distance.

Frightening things, angry feelings, things whose meanings were unclear—once converted into letters, they became a "single record."

And once turned into a record, they would no longer endlessly spin only inside his head.

"The Machine" appearing in this story was also depicted as a symbol representing such struggles of Masataka.

Did it truly exist externally?

Was it something within Masataka's perception?

Or was it a complex combination of memories, emotions, and imagination?

That answer is left to the reader.

The one thing that can be said is that, for Masataka, it was "an experience so significant it felt like reality."

Precisely because of that, even while suffering, he attempted to understand it.

And over a long time, he arrives at a single conclusion:

To gain something, you do not necessarily have to suffer.

This statement was the most important conclusion in this story.

People sometimes try to give meaning to their suffering:

"Because I endured this much, I must gain something."

"Because I worked this hard, results must appear."

"Unless I suffer, I cannot become my true self."

People tend to think that way.

However, life is not necessarily a set of trade-offs.

It does not mean suffering was useless.

Nor does it mean failure carried no meaning.

It simply means that suffering itself does not need to be made into a necessary sacrifice for life.

Masataka comes to realize that.

And there was another thing he reclaimed:

The sensation of choosing for himself.

Rather than waiting for someone to give him an answer, he thinks for himself.

Rather than being rushed by something, he decides his own pace.

If frightened, he stops.

If he doesn't understand, he thinks while leaving it ununderstood.

If necessary, he consults someone.

And he treats his life as his own.

That by no means implies "doing everything alone."

Rather, precisely because it is his own life, he can choose to seek help.

He can choose to rest.

He can choose to start over.

He can choose to proceed down a different path.

What Masataka gained at the end was not the power to solve every mystery.

It was the power to move forward even with mysteries remaining.

That is why, at the end, he closes the notebook.

In the notebook, about one year and eight months' worth of words remain.

There is fear, anger, hope, and confusion.

There are erased letters.

There are rewritten words.

There are traces of passing through the exact same place many times.

Rather than erasing all of them, Masataka leaves them as they are.

Because they are proof that he walked his path.

And he raises his head from the final page.

The outside world is no different from yesterday.

There are people in the city.

Cars are driving.

News streams on smartphones.

When morning comes, a day begins; when night comes, a day ends.

The world does not change dramatically just because Masataka found an answer.

What changed was Masataka's own perspective.

Previously, he sought meaning in every event.

Now, he feels it is fine not to decide meaning in a hurry.

What is unknown remains unknown.

Images are images.

Memories are memories.

Emotions are emotions.

And within reality, one simply needs to do what one can, one step at a time.

He became able to think that way.

This story ends here.

However, Masataka's life does not end.

Rather, it continues from here.

It is fine to carry the past.

It is fine to remain uncertain.

It is fine not to have a perfect answer.

It is fine not to know about tomorrow.

Simply valuing one's present while advancing one day at a time is enough.

And if anxiety returns, he can simply open that notebook.

There lie the words left by his past self.

Rereading those words, Masataka will surely think:

That long time did not exist merely to solve everything.

It was time to look at himself once again.

The phrase remaining on the final page is just one:

"It's alright now."

Those words are not words to throw away the past.

Nor are they words of giving up.

They are words to no longer imprison oneself inside the past.

And the words that follow next are—

"From now on, I will live by my own will."

The notebook is closed.

The pen is set down.

Morning light streams in through the window.

Masataka stands up.

And toward a future where nothing is decided yet, he quietly steps forward.

—End