One full moon night, Doi Sensei and Yamada Sensei are out on ninja duty. To avoid suspicion, Yamada-sensei disguises himself as lady Denko. Suddenly, the moon begins to glow due to a total lunar eclipse and a light shine down from the full moon taking the disguised Yamada Sensei to the moon. In order to save Yamada Sensei, Rantaro, Kirimaru, and Shinbei board a ducky spaceship and head for the moon, guided by a moon rabbit. This is the second installment of the popular "Ninja Boys x Cosmic Front" series, which also unravels the mysterious relationship between the moon and the earth! Let's go on a great adventure to the moon with the Ninja Boys!