Mutaguchi and his associates attempt to hire Tsurugi to kidnap Sarai, the daughter of a recently deceased oil tycoon. Tsurugi refuses after discovering that the gangsters are Yakuza. He escapes, but the Yakuza gangsters resolve to kill Tsurugi as well as kidnap Sarai. Tsurugi immediately seeks out Sarai, who is being protected at the Nippon Seibukan dojo by her uncle, Kendō Masaoka, a Karate master. Tsurugi captures Sarai and challenges the entire dojo to a fight. He brutalizes the rank-and-file students before Masaoka fights him to a standstill—then recognizes him as the half-Chinese son of a karate master he knew long ago. Ultimately, Tsurugi offers to protect Sarai, and Masaoka agrees, against Sarai's protests. Meanwhile, the Yakuza's allies in Hong Kong, led by Kowloon boss Dinsau, recruit Shikenbaru to avenge his siblings by killing Tsurugi.