From Chibi Manga:
17 years old, the person she fell in love with was, her teacher

Aiko has never been in love before. Even so, a boy whom she met from her first mixer suddenly brought her to a hotel! Aiko was helped by a man, at the time she was in a pinch and she fell in love to him. She met him again at school ,like a destiny but, he is a teacher at aiko's school...!?

Sweet and lovely, pure forbidden love story