Kemumaki disguises himself as the three main female characters in Ninja Hattori-kun and causes trouble for Kanzo.
Kemumaki is being taunted by Hattori, who is using his Ninja Techniques in a video. Kemumaki resolves to get revenge on Hattori using his disguise techniques.
One day, Mrs Mitsuba goes out shopping. Kagechiyo, who has been spying on them, goes to his master's flat. He tells Kemumaki about his opportunity to bother Hattori, and the two prepare.
Later on, Hattori and Kenichi are studying, while Shinzo and Shishimaru play hide-and-seek. Shishimaru finds Shinzo hiding in the bath, but when he goes into his kennel, Shinzo can't find him. All of a sudden, Yumeko Kawai (who, in reality, is Kemumaki), turns up. She - or he, gives them a box of digestive biscuits. The trio (Hattori, Kenchi and Shinzo) guzzle the whole lot up, while Shishimaru anguishes in his kennel.
Meanwhile, Kemumaki and Kagechiyo prepare some hamburgers, ready to cause some more trouble. At the Mitsuba house, Hattori, Shinzo and Kenichi roll around in their seats, their stomachs bloated with food. Just then, Kemumaki turns up in the guise of Tsubame, laden with a bindle of hamburgers. She asks if Hattori wants any of them, and Hattori politely refuses - but he then sees "Tsubame"'s eyes welling with tears, so he guzzles them up for her sake. Kemumaki gives a silent but evil laugh as Hattori's stomach inflates. "Tsubame" then runs off. When Shinzo asks his brother how Tsubame and Yumeko knew that Mrs Mitsuba wasn't around, realisation dawns on his face. He goes to Kemumaki's flat and spies on his rival disguising himself as Mrs Mitsuba.
At home, Shishimaru tells Kenichi and Shinzo off for not telling him that they had food. Just then, Hattori comes in and discusses a plan with Shishimaru so that he can get revenge on Kemumaki and so that Shishimaru can eat something. Just then, Kemumaki, disguised as Mrs Mitsuba, turns up, laden with dumplings. As Kenichi and Shinzo refuse, Hattori complies. Kenichi and Shinzo pretend that nothing's going on and tell Hattori that he might get a stomach ache, but Hattori doesn't listen. He guzzles up the whole lot. Just as he finishes the last bite, Mrs Mitsuba reveals herself to be Kemumaki. Kagechiyo turns up as well, having filmed everything. Kagechiyo turns his camcorder on to film his master throwing a stinkbomb at Hattori - however, when everything clears up, Shishimaru is seen wearing Hattori's hood. Kenichi and Shinzo pretend to be incredulous; however, Kagechiyo and Kemumaki are horrified. Just then, Hattori, headless, jumps off the ceiling, and reveals his head, having used the ninja technique of turtle-neck, and puts a balloon out of the middle of his robes. He then reveals the technique, and says that his head was Shishimaru, who was eating the dumplings while Hattori blew the balloon. Later on at their flat, Kemumaki and Kagechiyo lament that they emptied their fridge for nothing.