Looking For Information About A Japanese Movie

Hi I've been looking for a movie for a while, it's a Japanese movie I had on a hard drive but I lost it and can't remember the name so the movie starts with a student who is being harassed by others students and is saved by a boy student they become friends and a few years later they find themselves as a coworker in a job after he learns that the boy who had helped him was in fact a girl all this time and that he keep pretending to be a boy after the rest is easy to guess lol