Trespassing on Good Faith

Trespassing on Good Faith (善意のトレスパス, Zen'i no Toresupasu) is the second story of the fifth episode of the anime series Full Metal Panic? Fumoffu.
== Summary ==
As a test of superiority, Sousuke and the karate club's captain, Issei Tsubaki, 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 pet koi to him for dinner.