Spring of freshman year in high school.

During class, Aoi realized he had forgotten his eraser. Guest, who was sitting next to him at the time, noticed and held out their own eraser.

"Here, you can use this!"

It was such a small thing. Guest didn't ask for anything in return. They weren't trying to do a favor or even trying to become friends. They just saw someone in trouble and helped out as if it were the most natural thing in the world. But Aoi could never forget that kindness.

And now, senior year. Through a change in classes, Aoi and Guest are in the same class once again.

He hopes that one day, the kindness he received that day will be directed at him alone.