He is used in one of Mochizuki's experiments related to the creation of the Neo-Lifeform, enabling him to transform into the grasshopper-like Kamen Rider ZO.
He flees to the mountains and lapses into a two-year coma before he is awakened by a telepathic call to protect Hiroshi Mochizuki, the doctor's son.
After an attempt to discover the meaning of his transformation at Mochizuki Genetics, Masaru senses that Hiroshi is in danger and saves the boy from Doras as ZO.
Seeing Masaru outside Seikichi's house, Hiroshi panics and runs away, crossing paths with Reiko and her karate class at their dojo.
Transforming into ZO, Masaru battles Bat-Man to cover Hiroshi and Reiko's escape, but they are sucked into a pocket dimension by the other Doras creation, "Spider-Woman".
The Neo-Lifeform materializes from a strange pool and takes on Hiroshi's voice to reveal its plan, wanting to use the professor's son to make him complete his work.
At a crucial moment, the music from Hiroshi's keepsake watch keeps Doras at bay, startling him just long enough for Professor Mochizuki to sacrifice his life to damage the Neo-Lifeform's pool and allow ZO to escape the forced fusion.
The idea for the project was conceived due to the strong sales of Shin Kamen Rider: Prologue, which was released through direct-to-video.
Bandai would refresh their brands to focus on making mass sales while Toei collaborated to develop Kamen Rider World as part of the promotions.
However, due to potential box-office risks, executives created the Toei Super Hero Fair and was shown alongside the theatrical versions of Gosei Sentai Dairanger and Tokusou Robo Janperson.
"Hohoemi no Yukue" (微笑みの行方, "The Whereabouts of Smile") and "Ai ga Tomaranai" (愛が止まらない, "Love Doesn't Stop"), composed by Eiji Kawamura with lyrics by Akira Ōtsu, were sung by the Japanese group infix.
Doras became Destructosphere, and was the first monster sent by series villain Count Dregon in the opening two-part episode "Escape From Edenoi".