This is propaganda disguised as a fairy tale, and it works because the fairy tale part is honest. Momotaro's animal crew are given actual personalities, loyalty, sacrifice, real stakes. The film doesn't condescend to its audience or the war it's selling; it builds the emotional logic of the mission so carefully that by the time the bombs fall, you understand exactly why these characters chose to go. Watch it to see how animation became a weapon, and how a weapon tried to become art.
Momotaro leads a surprise air raid on the ships of Demon Island, with his animal companions serving as the crew and pilots of the attacking aircraft. The short film was government funded wartime propaganda, and it is regarded as the first animated feature made in Japan. It puts the folklore hero and his animal friends into an attack modeled on Pearl Harbor. The defenders look strikingly like Bluto and Olive Oyl from the Popeye cartoons. Real footage of the Pearl Harbor attack, supplied by the military, is cut in alongside the animation.