Sousuke and Kaname ask the school's karate club to vacate their dojo, which is slated for demolition. However, the club refuses to leave, challenging Sousuke to a duel where they'll leave if they lose. Sousuke defeats the club's members with relative ease until he faces the club's captain.

As a test of superiority, Sousuke and the karate club's captain compete to care for the injured school janitor; however, their overzealous efforts do more harm than good. The janitor tries to be patient, but finally goes berserk when they accidentally serve his prized koi pet to him for dinner.