It's mandatory sex class, and the narrator is relieved. He wonders what his family is like in this new world. He's happy that his parents are still normal, but he's also happy that he and his friends have done the sex act together. He tells us that his friends tease him about being a virgin, but they don't have the mark. He also tells us about the teacher who lectured him the day before, and how embarrassing it was. He and his friend, who is on the table-tennis team, had sex for the first time, and they're both very happy about it.