While I think explaining a story can sometimes feel unnecessary, I’ll give it a try...
In this game, the player takes on the role of a teacher who enters a school and begins to experience the life of a new transfer student. The teacher/player witnesses the whispers, mocking and bullying directed at the student. As the teacher enters the classroom, he begins to relive his own actions towards his students. He remembers how he would casually inquire about their well-being but never truly cared to understand what was really happening to the transfer student—or to any of his students.
Throughout the game, the player's identity shifts several times. They embody the transfer student, the teacher, and another bullied student who interacts with the transfer student(in the locker). In the later act, the transfer student realize just hiding would not stop other students from bullying, he begins to seek revenge, and the teacher/player is left as the last one standing. The ending leaves it to the player's imagination to consider what fate might await him.
I realize this might be a bit hard to follow, but I'll try something less complex next time... maybe.