The only brother you (Ryosuke Kawamura) and his best friend were bullied and killed by several bad teenagers, and the police who accepted bribes judged it to be suicide, which made the originally cheerful and happy high school birthday Gao Yamei (eight generations of Yoshimi) resentful. However, Toukimura Xiang (Nishihara Yuyu), a bad teenager, not only has an underworld background, but also a descendant of Hanzo Hattori. Instead of getting revenge, Ami had her arm cut off. In times of crisis, the parents of his brother's friends, Sugihara (Ishikawa) and Miji (Yasami), who run the repair shop, survived with the help of a modified arm that could even be fitted with a powerful machine gun. Yamei and Sugihara once again embarked on the road of revenge.