The Harumichi Family is a group of students who were unofficially considered Harumichi Bouya's faction at Suzuran. Even though Harumichi himself didn't recognize them as such, considering himself a loner, but they are all extremely loyal to him and would fight on his side at a moments notice. As for Harumichi, he values them as good friends rather than his "faction" of delinquents. The group consists of the Ebizuka Trio, Akutsu Futoshi, Sagawa and Yasuo Yasuda or, hilariously, Yasu the Razor. The "number two man" in Harumichi's group--supposedly, at least.
At their peak they got 46 followers and the Ebizuka Trio joining in to fight T.F.O.A., making it 49 members - 50 if you count Bouya.
During his first year, Zetton, who was an underclassmen of Harumichi's since mid school, would also briefly follow this group along with his freshmen classmates.