Purpose of Tutoring

Yeong-tak and Ha-na are siblings who live on the support of their divorced adoptive parents. They both start taking private lessons to develop their careers. One day, Yeong-tak secretly gives his instructor Na-ri sleeping pills to possess her, while Ha-na is busy seducing gym teacher Han-cheol. Meanwhile, Na-ri and Han-cheol meet by chance at Yeong-tak’s house, fall in love at first sight, and decide to seek revenge on the two people who offended them.