Nagi Souichiro is a typical street bully. For him and his friend Makihara Bob there has never been a problem with taking over the control in the schools they have been in. But the Todo martial art school is different. On the first day in the new school against him appears a little girl, who suddenly turns into a sexy babe. In their fight he is powerless against her. A moment later he bumps into her little sister, who decides that she must marry him no matter what. In charge Nagi’s training is Natsume Maya (the same little girl who defeated him). His potential is huge, but some strong feeling emerge between Soighiro and his master. The sister, of course is not at all happy about it. Nagi is in a very confused situation, but he isn’t smart enough to realize it. The main reason for him to exist is to become stronger. He doesn’t have any respect for anyone. Despite his hard training he always acts like an arrogant street fighter.