During a campus play, a 'relationship training' game turns real as lifelong friends cross boundaries and slip into a secret romance.
Jun Xi and Han Tuo grew up together and have a close relationship. Now in college, Jun Xi asked Han Tuo to help him with love, from watching a movie to almost kissing, with every step challenging their relationship. When they travel to a beach, the two stay in the same room, and the ambiguous atmosphere becomes more and more exciting.
After the trip, Tuo and Jun Xi are forced to play the leads in a school play and end up kissing. Tuo admits his feelings towards Jun Xi and the relationship guidance was just an excuse, but Jun Xi struggles to accept his own feelings and the two start fighting.
Jun Xi doesn't know how to deal with Tuo's confession, and keeps his distance. Eventually, the two reconcile and try to have a romantic relationship, but Jun Xi remains uneasy putting forth conditions.
Jun Xi and Tuo start to get along, but they are unable to be more intimate, while a confession from a female classmate causes the two to argue again. Jun Xi takes the initiative and breaks a rule.
Jun Xi prepares a birthday gift for Tuo, but they end up in a fight. After learning the truth, they reconcile, but a new obstacle awaits them…
Jun Xi discovered that Tuo had tried hard to change in the past in order to attract him. After being accepted for the internship, Jun Xi decides to propose living together. However, Tuo's relationship with his father becomes increasingly strained, and he even forces him to move to Kao Hsiung, which puts their relationship in jeopardy.
Just as their life together seems to be on track, Han Tuo is forced to take care of his nephew, who gets in the way of the couple's cohabitation. The pressure of the internship and the young child exacerbates Jun Xi's insecurity, and he begins to doubt the relationship.
