Nobody talks about this one. A 1930s propaganda film that trades the sky for the ocean, swapping mechanical spectacle for the genuine strangeness of deep water, Momotaro piloting a submarine to fight a giant shark is exactly as surreal as it sounds, and the film leans into that weirdness instead of fighting it. The animation captures something most early anime never attempts: the alien weight and pressure of being underwater, where even a folk hero looks small. Watch it for the historical curiosity. Stay because it moves like nothing else from that era.

Momotaro and his friends are called on to help bring down a giant, vicious shark. To do it, Momotaro has to go down into the ocean, and he takes the fight to the beast in a submarine. The film was made after Momotaro in the Sky (1931) proved popular, and it moves its hero from the air to beneath the waves.