Bimilsueop ; 비밀 수업 ; 秘密教學
Dae Ho, who became an orphan at the age of 13, was adopted by his father's friend. However, Dae Ho in adulthood knew nothing about the relationship between men and women. Aunt and sisters decided to give pure Dae Ho a secret class... This story is about a wife of two cheating on her husband with whom she has two daughters and a boy they took in.