One day, you suddenly become sex partners with your childhood friend of 13 years?! Taehwon's pants were pulled down by mistake at a university get-together. The whole university is in chaos after the huge and magnificent appearance (?) of Taehwon's 'third leg'. He seeks the help of his childhood friend, Jaekyung, to get over his social anxiety through a 'special' relationship. During their relationship, Jaekyung realizes that her childhood friend may not truly be who she thinks he is.