Kemumaki disguises as Kenichi and plays a nasty prank.
Kemumaki and Kagechiyo are at the park, and Kemumaki demonstrates a disguise technique. He then remembers that it's Valentine's day, and decides to play a nasty prank!
Kemumaki disguises as Kenichi and receives a chocolate from Yumeko, who is distributing some of the confectionery. Later on, he takes his disguise off and receives another chocolate from Yumeko. Poor Kenichi sulks - Kemumaki received two chocolates while he received none!
Back home, Kenichi tearfully informs Hattori and the gang of his disadvantage, and they promise to help however they can. Hattori then disguises as Yumeko and meets up with Kemumaki to tell him off about his prank. Kemumaki, daunted, gives one of the chocolates back to Hattori and flees with Kagechiyo. In the meantime, the true Yumeko realises her mistake and apologises to Kenichi. As Shinzo and Shishimaru badger Yumeko for chocolates, Kenichi shoots them dirty looks, but Hattori is amused.