Madarame-sensei no Mousou Gakkyuu Nisshi

Madarame is a teacher who has a really strange personality. Whenever she is in trouble or has to make a decision, her minds splits into three parts—a leader, a maiden, and a slob—who argue about the outcome. When her boyfriend breaks up with her, she goes a bit wild. She cuts her hair, and then goes out and gets in a fight, ending up dumped on a pile of trash. At her lowest, one of her students, Sena, rides up on a "white horse" bicycle and takes care of her wounds. Is her student Sena her prince on a white horse, finally come, or is that just ridiculous? Now, Madarame has an absurd crush on her student that she just can't seem to shake.

(Source: MangaHelpers)