Gu Hai beats his physical teacher's by doing more than a hundred pull-ups. Luo Yin plans his revenge against Gu Hai by sewing his school jacket shut, resulting being sent out by his math teacher for creating a ruckus. But during their English language lesson, a sleeping Luo Yin accidentally chided his teacher, thinking that it was Gu Hai who disturbed him. With several revenges acting amongst Gu Hai and Luo Yin, Luo Yin plots a new scheme by buying mechanical oil and locking the classroom doors. Unbeknownst to Luo Yin, this act would ultimately make him look bad as Gu Hai calls the school's principal in the class while telling him on a sticky note that it was Luo Yin who ruined the doors. The next day, Luo Yin receives breakfast after arriving to class and thinks that it was an act from You Qi. (Source: IMDb)