Sensei, Watashi ni Ochite Koi!

Runa has a crush on her kind and handsome teacher, Mr. Itsuki. But one day, she discovers his true nature-he's not the person she thought he was at all. Instead of the caring teacher she admired, he's manipulative and unethical. Now, her school days are filled with him teasing and tormenting her, and even though she knows she shouldn't take him seriously, she can't help the way her heart races whenever he's around. This is the story ofa complicated and forbidden attraction between a high school girl and her teacher.

(Source: Kodansha, translated)