High School Girls are Funky (HSGF) is a mini-series that focuses on the lives of three high school girls, who are secondary characters in the main series. It is set in the same locale as the main series and is presented through extra chapters at the end of each volume (in the manga) and extra shorts at the end of each episode (in the anime).
Much like the main series which centers on a trio of boys, HSGF features a trio of second-year high school girls: Ikushima, Habara and Yanagin. Their stories have them goofing around, trying to leverage their ‘high school girl power’ and occasionally interacting with characters from the main series, among other things.
Yanagin is a student of Sanada Central High. She is the tomboy of the group and is outspoken, brash and sometimes even vulgar. Among the three, she despises boys the most, characterising their lives as ‘pathetic’ and insisting on the superiority of girls. To this end, she is frequently seen boasting about ‘high school girl power’ and the inevitable popularity of high school girl characters, and also trying to boost this so-called power. She takes her job of monitoring Habara seriously.
Ikushima is a student of Sanada East High. She is usually cheerful, but prone to crude behaviour sometimes. This usually happens under Yanagin’s lead, or when the two of them pick on Habara. Like Yanagin, she also holds various preconceptions about the shortcomings of high school boys and can be quick to anger. However, her behaviour is not as extreme as Yanagin’s. She actively entertains the thought of getting a boyfriend, unlike the others.
Habara is a student of Sanada West High. She appears the most reserved of the three, and sometimes seems entirely out of touch with the others’ antics. She serves as the ‘straight (wo)man’ of the trio. Unlike Ikushima and Yanagin, she barely thinks of boys at all. She is also relatively soft-spoken and polite. The chasm between her and many boys her age is revealed to be an outcome of the violent story associated with her childhood.