A co-production between Toei Company, Bandai, and Ishimori Productions, it was the final story in which Shotaro Ishinomori was involved, who died 4 years later.

After conducting a praying ceremony, the three oldest children of the alien Fog Mother hunt for an ideal human to feed to their newly hatched siblings.

Absorbing the life energy around him, J kills Fog Mother's newborn offspring, escapes from her bowels, and assumes the Jumbo Formation.

Escaping Fog Mother's destruction, Kouji brings Kana to a peaceful place as Berry watches from a distance.

In the film's climax, he is summoned (in giant form) by Kamen Rider Diend to battle King Dark.

Hachi Woman became Hydrasect, appearing in the episode "Stranger from the North" with a monster from the previous film Kamen Rider ZO.