One day, a massive technology capable of turning the world upside down is announced.

It is 'Mnema,' a memory device named after Mnemosyne, the goddess of memory.

This innovative device, which can perfectly erase memories in the head, allow one to rewatch them like a movie, and even create new memories that never existed, completely changes the paradigm of the era upon its launch.

And then, 'Mnema Corporation,' a giant high-tech company that exclusively manages this overwhelming technology to heal and remodel human memory, emerges.

It offers Replay, which expresses deep memories in the unconscious and visualizes them on a monitor; Injection, which directly injects fake scenarios or illusions into the brain to rewrite the perception of reality; and Erasure, which blocks neural connections related to specific events or people.

---

Yeon Sinu, 23 years old.

189cm tall with broad shoulders and striking looks. The youngest son of a chaebol family who grew up with everything he could ever need, he currently lives alone in a luxury penthouse in the heart of the city.

Looking at his conditions, it seems he would have nothing to fear in the world—

But Sinu is naive and innocent, completely out of touch with the world, in a way that doesn't suit his flashy background at all.

He trusts people easily and can't say a single harsh word. Moreover, he is so shy that even the slightest embarrassing event makes him turn red from his ears to his neck.

Recently, a problem arose for Sinu that even money couldn't solve.

It all started one ordinary night at his penthouse.

Late at night, with no appointments and no one expected to visit.

Sinu was all alone in the spacious house.

At least—

That's what Sinu thought.

In his home, where he believed he was perfectly alone, he settled comfortably on the sofa and was spending a deeply personal and private time that he would never, ever do in front of others.

But at the moment he was most off-guard.

Beep— Beep— Beep—

The sound of the door lock came from the entrance.

"...?"

The only people who knew the passcode to this house were his family.

No way.

The moment Sinu looked at the entrance with a frozen face—

Click.

"Sinu-ya."

His parents walked in without any prior notice.

"...."

"...."

"...."

The eyes of the three people met exactly.

It was too late to run.

The situation was too obvious to pretend nothing was happening.

Above all—

They had already seen it.

His own parents.

Of all things, the moment in his life he least wanted to show anyone else.

"...Ah."

The 189cm giant froze right there.

Since that day, hell began for Sinu.

His parents tried their best to act as if nothing had happened. In fact, no one even brought up that day.

The problem was Sinu.

Even just making eye contact with his parents at a family dinner brought that day back to mind. Even if his mother called or his father just looked at him for no reason, he couldn't help but think.

Surely they aren't thinking about that right now.

It was worse at night.

As soon as he closed his eyes, everything from the sound of the entrance passcode to the moment the door opened and the moment he made eye contact with his parents came back to life as if they had been waiting.

"Uwaaaa...."

Nights of writhing under the covers repeated.

If only he could just take the memory of that day out of his head.

He thought it was an impossible wish.

But now—

It was actually possible.

The technology to directly view and edit human memory,

Mnema.

And the memory-specialized institution that exclusively operates that technology,

Mnema Corporation.

A place where memories can be played back like movies, emotions can be blurred, and if desired, specific memories can be deleted in stages.

Complete deletion required a total of 10 treatment sessions.

But no matter how embarrassing the memory, he was afraid of completely erasing a part of his life.

So Sinu compromised.

5 sessions.

He didn't need to forget completely.

If his parents' expressions became a bit blurry, the situation at the time became faint, and he could reach a point where he wouldn't kick his blankets even if he remembered that day.

That was enough.

And on the day of the appointment.

Sitting in the reception room of Mnema Corporation, Sinu couldn't move his pen for a long time in front of one item on the application form.

[Please describe the memory you wish to treat in detail.]

"...."

His ears turned red, and his neck heated up.

After writing and erasing, then writing and erasing again, he finally left one sentence.

I was caught in a state that I should never have shown to my parents.

And below that, he added a small line.

Please don't ask for details if possible.

Carrying that one memory he never wanted to be caught with again—

Yeon Sinu came to Mnema Corporation.

He doesn't know yet.

That in order to treat the memory he wants to hide so badly,

Someone must look into that memory first.