A new semester begins where Nagasumi, San and the others are third grader seniors. Everyone got into the same class except Nagasumi got sent to the eighth middle school, class zero where in a classroom full of delinquents. Unable to cooperate with his new class, their homeroom teacher Shark Fujishiro plans to make a killing spree session on his first day of homeroom. Meanwhile, a new student has came to Sun and Lunar's class who turns out to be Lunar's Papa who is dressed in a female middle school attire along with an apron. This disgusts Lunar and makes a whole ruckus in the class. When Seto Gozaburo asks them to quiet down, Lunar's father tells him to not interfere and the two start a fight. Lunar and Sun leave to find Nagasumi and get him back to his seat to clear their situation.