I believe its one of the last ep. Takamura tells his story. He was a highschool delinquent, beating everyone around him and beign very bored. Then one day he meet the coach and offered to become a boxer. He says fuck it, walks away. Then he meets Miyata and try to beat him up as well, but fails miserably and decide to accept coach invitation.
I maybe mistaken in the detils, watched it too long ago.