Ryou Takagi is a high school student and a trumpet player in a jazz band. However, he is also a vicious brawler who earned himself the nickname of B.B on the streets. This stands for "burning blood", because of the way he lights up with rage whenever he gets serious in a fight.

His reputation as a brawler gets him into a lot of trouble with various street gangs, but when one gang goes too far and takes advantage of his friend's partner, he deems to send all of the gang members to hell. However, this gang hired the help of a prestigious fighter by the name of Jin Moriyama, who gives Ryou a run for his money, leaving him lying face-down in the dirt.

After feeling helpless at his defeat by the hands of Jin Moriyama, Ryou learns that Moriyama practices boxing. It's at this moment he decides to put all of his effort into learning the sport of boxing, and attempts to get a boxing club created at his school.