Yoshitake's older sister/In the Series

High School Boys and Seniority
Yoshitake's sister makes her debut as one of Mino's friends with her near the station. She is the only one in her group from Central High, and remains unnamed in this sketch. After Mino introduces her younger brother and he greets them, she and her friends form a circle around him, cutting off his escape. They then start toying with him mercilessly, first making comments about his goatee, and Yoshitake's sister suggests shaving it off.

One of Mino's other friends comments that he looks like a comedian who's famous for a certain catchphrase. The rest of the group starts laughing and they eventually force Motoharu into repeating the same catchphrase for them. Yoshitake's sister then picks on him for his hairstyle. The others suggest altering it and they pull out hair bands to make twin-tails of his hair. They all laugh at him again.

After they're done humiliating him, Motoharu tries his best to escape. It is in vain, however, since Mino's friends are revealed to be coming to their house for a sleep-over that night.

The end scene shows Yoshitake's sister and another girl holding a screaming Motoharu back, as a third girl brings a razor towards his chin.