This is a 1930s propaganda film that transcends its purpose. A country of peaceful frogs faces invasion by devils, and the film treats it with the weight of actual tragedy instead of cartoon simplicity. The emotional core is real: ordinary creatures watching their world end, not understanding why killing has to happen. Made as a warning Japan ignored, it became a document of the moment before everything changed. That weight never leaves you.

A peaceful nation of frogs comes under sudden attack from a country of devils. Bombers launched from a floating platform strike from the air, cat-like creatures attack from sea-planes, and the assault grows fiercer after dark. General Korokichi the frog orders his people to fight back, and they answer with searchlights and anti-aircraft guns. The film was made to raise awareness of crisis at a time when Japan stood close to war with China, a war that broke out the following year.