Love Dissonance.

The story takes place in a certain high school. Masaki Nitta arrives as a new music teacher, but the school is greatly disturbed by the disappearance of the previous teacher. While playing the piano in the music room the night before work, Masaki meets Sae Izumi, a student who is running away from one issue. Sae is a student in the class in which he is an assistant teacher. The two of them, gradually develop a bond through the disappearance.