Avsnitt 3

A month following their last encounter, the girls prepare to face off against the fifth Vertex, only for another hero named Karin Miyoshi to suddenly appear and defeat it single-handedly. The next day, Karin transfers into Yuna and Mimori's class, claiming herself to be a fully trained hero sent to supervise the newbies. She reluctantly joins the Hero Club, though is stubborn about becoming friends with the others . That weekend, as the girls plan to meet somewhere, Karin skips out on it, feeling she should not be led astray from her duty as a hero. Later that night, the girls show up at Karin's apartment, revealing they had planned to surprise her with a birthday party. At the end of the day, Karin is starting to get along with them.