Osu!! Karatebu Manga

The series began as a fairly humorous and lighthearted satire of Japans teenage delinquent-gang subculture told from the perspective of Matsushita Tadashi (who also narrates these early Karate Bu stories), a 2nd year student at Kangokou High and a constant target of Kangokous numerous bullies who beat him up routinely after school. He is almost always accompanied by his best friend Saitou Takaki, who is also constantly harassed. As the pair grow increasingly tired of being victimized they decide to join the titular Karate Club, which is notorious throughout Osakas youth gangs for training and producing the citys most hardened and toughest teenage thugs while maintaining the facade of a legit school sports club. But when they join the club, they find themselves picked on just as much if not worse by the club's current members. But as the story progresses they grow to be increasingly capable fighters.