Du-yeong, just back from serving in the military, is suffering from an acute case of “sad nipple syndrome.” If anything so much as grazes his nipples, Du-yeong falls deep into a depression. This negatively affects his ability to make friends and has left him a loner at school. Even when at home, Du-yeong wears a brazier to shield his nipples. In-a, a friend from school Du-yeong has a crush on, runs into him wearing a brazier when Du-yeong opens his door to pick up some delivery food, at which point he makes up his mind to have his nipples surgically removed.