A theatrical release of The Return of Ultraman episodes 13-14. It was released on December 12, 1971 as part of the Toho Champion Festival along with Godzilla, Mothra, King Ghidorah: Earth's Greatest Battle (edited from Ghidorah, the Three-Headed Monster) and shorter versions of The Adventures of Hutch the Honeybee, and The Little Match Girl.

A physicist named Tetsuo Okita discovers a new mineral called "Satanium," which is more powerful than uranium and emits destructive effects to anyone exposed to it. However, Destron abducts Okita in hopes of finding the source of Satanium and collecting more of it to expedite their run for global domination. Kamen Rider V3 must act fast in rescuing Professor Okita and preventing Destron from collecting more of the deadly mineral.

Follow the adventures of Shiro Kazami, a bio-chem major at Jonan University in Tokyo. After witnessing the murder of a member of the evil organization Destron, Kazami is targeted by Destron which kills his family and leads him down a road of revenge that crosses paths with both Takeshi Hongo and Hayato Ichimonji, the original Kamen Riders and his eventual transformation into Kamen Rider V3!