During the summer, they are challenged by a group of rival ninjas which culminates in a race to ring a bell on top of a mountain.
Rantaro is sent by his father and mother (Shido Nakamura and Rei Dan) to attend the six-year course at a Ninja Academy run by Denzo Yamada (Susumu Terajima).
After going home to his parents' farm for the summer holidays, Rantaro is joined by his schoolmate Shinbei (Futa Kimura) but they later decide to stay with Kirimaru (Roi Hayashi) and teacher Doi.
One day, some Usutake ninjas arrive at the house of flamboyant hairdresser Yukitaka Saito (Takeshi Kaga) and his son Takamaru (Takuya Mizoguchi) in order to kill both of them.
Yukitaka and Takamaru used to belong to the Uuetake clan, but Rantaro and his friends aim to save them by joining a contest that ends with a race to ring a bell on top of a mountain.
[6] Tradepaper Variety gave the film a favorable review stating that it had "joyous energy that propels its pint-size protagonists through a rapid-fire succession of slapstick gags, each more outrageous than the last".