Ren Takahashi has a perfectly ordered life. Endless shifts, cans of energy drinks, and a desk that’s always spotless. No friends. No family. No mistakes.

Until one morning he finds an envelope with no return address on his desk.

The seal is old.
The paper, yellowed.
And his name written on the front.

Inside there is something he doesn’t remember. Something the past left behind.

Or that never left.