Oyoge ya Oyoge

Animals are participating in a swimming contest. Saru-kun, a proud monkey, can't admit he can't swim and enters the competition. He dives in but starts to sink. The pool's bottom is filled with seaweed and coral, and a kappa, a water imp, lives there. Saru-kun fights the kappa and takes its head saucer. The kappa agrees to let Saru-kun ride on his back while swimming in exchange for the saucer's return. Saru-kun wins the race, appearing to swim on his own. But what happens in the end?