Yuji Takehisa

The strongest delinquent of Hekikuu high, previously expelled for beating up one of the teachers: after being defeated by Kitano, he proclaims himself his "little brother". He sports spiked bleached hair and has no eyebrows.
After claiming loyalty to Kitano, he becomes less delinquent-like. He doesn't get into a lot of fights anymore (although he doesn't lose any of his fighting skill), nor does he skip classes, staying calm most of the time. His old, hot-blooded self, comes to the surface when someone tries to harm Kitano or himself. At the end of the series, when confronted with the fact of Kitano being "normal" -Takehisa's old comrades had come and asked him to join up in order to beat up Kitano- he proclaimed that whether or not Kitano is a delinquent, he is still Takehisa's best friend. He then proceeded to beat up his old comrades with a smile on his face.

(From Wikipedia)