Aka Shura(しゅら アか, Shura Aka) is the protagonist and a reference of the series. He was an underground fighter who dreams to become a filmmaker. He was forced to join underground fight in Tokyo, to earned money for his father that has liver cancer and needs an operation. In the day, he was Aka Shura, a kind and gentle 4th year high school student but in the night, he has a secret identity named Blood(ぶらど, Burado), a cold and sadistic underground fighter.