Twelve year old Sei has hit puberty and is quickly becoming sexually aware, sometimes not as privately as he'd like; erections in school and other inopportune times plague him. He talks about it with his school friends, Kinta and Nyanko, in between their feuding over the affections of classmate Yumi, but can't figure out what to do about it.
Kimura wins a trip to Hong Kong, but once he arrives, he is mistaken as a hitman and is assigned to kill Yumiko, the female successor to the Ota Group conglomerate. When Kimura falls for his target instead, he must learn kung-fu from a local (Yuen) to fight off the yakuza assassin "Invincible" assigned to finish the job.
After Reiko moves from Japan to Hong Kong to start working for Jackie Chan, her boyfriend Daijiro, in a fit of jealousy, hops on a plane and heads for Hong Kong himself. He manages to land a job as a stuntman, but can't quite seem to win his girlfriend back. When a young woman from mainland China searching Hong Kong for her boyfriend shows up in Daijiro's apartment, an additional set of complications are added to the story. Will anyone find their true love?
