During WWII, Germans obtain the immortal heart of Frankenstein's monster and transport it to Japan to prevent it being seized by the Allies. Kept in a Hiroshima laboratory, it is seeming lost when the United States destroys the city with the atomic bomb. Years later a wild boy is discovered wandering the streets of the city alone, born of the immortal heart.

Tadao Takashima
as Dr. Yuzo Kawaji

Nick Adams
as Dr. James Bowen

Kumi Mizuno
as Dr. Sueko Togami

Yoshio Tsuchiya
as Daigo Kawai

Koji Furuhata
as Frankenstein

Jun Tazaki
as Hideo Nishi, Director of the Okayama Prefectural Police

Susumu Fujita
as Osaka Prefectural Police Chief

Takashi Shimura
as Hiroshima Army Hospital doctor

Nobuo Nakamura
as Dr. Suga

Kenji Sahara
as Tadokoro, Bowen's assistant