Based on the hit song, the story involves a young boy and girl who leave their home in Hokkaido to come and live in Tokyo.

A writer haunted by the death of his wife and threatened by the imagined infidelities of his lovers uses his affairs for the subjects of his novels.

In Osaka during the Edo period, ruler Sanada Yukimura was in losing position, fearing Toyotomi's blood descendents would end, he impregnates one of five Shinano female ninja with the seed of Toyotomi Hideyoshi in hopes of continuing the bloodline. Princess Sen and the five female ninja escape from Osaka castle by blending in with the handmaidens. Lord Tokugawa Ieyasu who was supposed to rule all under the heavens was informed of this secret. So Ieyasu orders five samurai of the Iga Ninja clan (brought by Hattori Hanzo) to stop the Toyotomi bloodline by killing the Kunoichi ninja. An attack of ninja magic arts unfolds in a battle of the sexes.

Koichi and Mariko are a married couple. Both husband and wife have their own careers. Koichi is a civil servant who returns home on time, while Mariko returns home late at night, leaving their love life cold.

1965 Japanese movie