Less than a year before graduation, the protagonist has to change schools, because his parents changed jobs to a town hundreds of miles from his old school and didn't want to rent him a flat at their old town.

Forced into a new school with no friends and closed circles hard to get into, one day he finds an anonymous note in his shoe locker, asking him to meet them in a classroom after school.

Halfway expecting someone to play a prank on him or a school gang aiming to rough him up and extort him for money, he still anxiously makes his way to the specified room...

[From Itch.io]