Read it 5-6 years ago, really liked it but for the life of me, can’t remember the tile TT_TT. The MC is a highschool student. She has a brother, her dad abandoned them I think. She has a crush on her teacher but I think he liked someone else and thinks of her as a kid. She meets a strange boy who takes a liking to her. His father physically abuses him because he thinks his wife cheated on him and had the son. The overall tone of the manga is tragedy, slice of life, very realistic in how it portrays human relationships. Please help me find it, I’ve been searching for it for 2 years now 😢

OCD you say...
Yaya?