The next day, Lin Su learns that his sister, rouer, has gone crazy at her dad's party, and that she is also Lin Su's biological sister. Lin Su is also the mastermind behind the whole thing, and he is the one who pushed Su Qiang's head in the toilet and drugged Rouer. He is also responsible for breaking Chi Siang's study desk, which is why he kicked it. Mr. Guhead, the social studies teacher at the school, tells the students that they will be required to complete a "social practice task" every semester. The task will consist of students forming into groups and choosing a research topic and conducting research on it. The students will then evaluate their social skills in order to decide which group they belong to.