Maro Ayanokoji, the history teacher of Class 2-F, asks Yamato and friends to search for his dog, who has a striking resemblance of his face. After a long chase across town, they wind up in the middle of a weapon warehouse. They are confronted by mobsters and ninjas. The girls manage to stave off the power of the criminals, but the criminals drop a bomb into the warehouse before making a quick getaway. Yamato and company walk away unharmed from the explosion, thanks to Momoyo, but they all soon remember what they were supposed to do in the first place...