A woman named Illy marries a man who was her teacher in high school and also meets another man.

Hee-Tae (Uhm Tae-Woong) met his future wife, Il-Ri (Lee Si-Young), when he worked as a temporary biology teacher at an all girls high school. Il-Ri was a student there.

Now, Hee-Tae works as a fishery researcher and spends his days in a typical marriage. One day, he learns that his wife is having an affair with a carpenter (Lee Soo-Hyuk). He becomes angry for the first time, but decides to keep his family and wife.