The manga I'm looking for is about this smart kid that was supposed to go to a good school, but ends up going to this school for delinquents (possibly by mistake). The school has a bunch of factions divided by grade level. The freshmen faction is divided further into two. One side is led by a charismatic yellow haired male with a green accessory (bandana?) and a useless sidekick and the other is led by a possibly silver/white haired male (who later takes some drug to become more powerful). It turns out the mc (smart kid) has a split personality, the other one being violent and more powerful (to the point of nearly killing the drug-boosted silver haired guy who defeated yellow guy after taking the drug).