As alien invaders plot to conquer the Earth, two Boy Scouts steal a mini-submarine and discover Gamera in their midst. Transported to the alien's spaceship, the Scouts are menaced by the evil inhabitants, including Viras, a squid-like monster that grows to colossal size to battle Gamera.

"The Time of Reckoning" transforms a screwball-comedy plot into a sober study of a successful businessman with serious relationship problems involving three women: his wife of ten years who announces she is pregnant by another man; a mistress who wants to have a baby with him; and an ex-lover who claims he fathered her son.

Eighth film in the long-running series Daiei Studio's Woman Gambler with Kyoko Enami starring where she plays the woman gambler Ogin.