The Harumichi Family is a group of students who were unofficially considered Harumichi Bouya's faction at Suzuran by the other factions at the school itself and their rival Gangs and Schools around the Town. Although Bouya Harumichi himself didn't recognize them as such, considering himself a loner, even so 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.