Whilst trying to catch a fish for dinner, Kaito meets Isshin Uminari, a boy from the fish market, who helps him catch a large tuna. As thanks, Kaito and the others help Isshin out at his store, which is struggling due to a lack of fresh fish in the bay. Upon learning Isshin is participating in the Hero Wars, Kaito decides to have a match against his hero suit, Piscesamurai. As Isshin gets the upper hand due to his samurai techniques, powered by the support of the people on the bay, he reveals the bay is in trouble due to a nearby factory polluting the ocean and reducing the number of fish nearby, with Isshin desiring to save it using the Hero Wars prize money. Kaito states that he joined Hero Wars not just for the money, but because he loves Hero Battles too, encouraging Isshin to do the same. The two proceed to battle to their hearts' content, with Kaito ending up as the winner. After the battle, Kaito decides to help out the market by buying all the fish with his prize money, much to Aki's dismay.