The dolphin show (Attending the Dolphin show) (消えたイルカの巻) is episode 347 of the 1981 Ninja Hattori-kun anime.When Kagechiyo falls into a pool at a dolphin show, it's up to Hattori and Kemumaki to save the day.
Hattori, Kenichi, Kemumaki, Yumeko, Shinzo, Shishimaru and Kagechiyo are at a dolphin show. Kenichi grumbles about the queue, and Kemumaki orders Kagechiyo to book seats for him and Yumeko. Kagechiyo runs off, but then he sees a bucket of fish. However, the manager says that the fish is for the dolphins, before blowing a raspberry at him and walking off.
Later on, the show commences, with a man throwing fish to the dolphins. All of a sudden, Kagechiyo jumps out of the pool and nabs a piece of fish. Yumeko points out that it's Kagechiyo, and Kemumaki says "Kagechiyo is insulting me in front of everyone!" Kagechiyo repeats his act, and swims underwater - only to be cornered by the anthropomorphic dolphins. He swims off, and, after some struggling with the grilles, he breaks them off and swims inside, followed by the dolphins. Hattori and Kemumaki do something they rarely do - join forces and help save the day. They hop into the pool and swim into the open grille. Arriving at the bank of a river a few miles away, they discuss what to do. Hattori offers to go back to the show and dress up as a dolphin, and tells Kemumaki to find Kagechiyo and the dolphins.
Back at the ticket office, Hattori disguises as a dolphin and goes back into the pool. Meanwhile, everyone is fretting about the dolphins. The fish thrower tells his "lovely ladies" to turn up, and Hattori the dolphin springs out of the pool. The fish thrower then holds out a hoop, which Hattori jumps through with ease.
Meanwhile, on the river, Kemumaki, who has borrowed a speedboat, drives to the show, with Kagechiyo and the dolphins in tow. Kagechiyo tells Kemumaki to drive faster before the dolphins eat him, and Kemumaki starts a tirade, telling him to shut up and think about his actions. Back at the show, Hattori the dolphin bounces a ball with his nose. He then somersaults, before going back into the pool. Kemumaki and Kagechiyo come back in through the grille, followed by the dolphins. As he, Kagechiyo, and Hattori the human go back to their seats, the dolphins return to their act. At the seats, Kemumaki chides Kagechiyo for his actions, and Kenichi and Yumeko wonder where the smaller dolphin (Hattori) got to. They ask Hattori, who innocently says hat he doesn't know.