Spectreman disguises himself as a Japanese man named Jôji Gamô to walk among the humans and scout out Gori's weekly menace for the Nebula 71 Star.

This group investigates phenomena involving pollution, but they do not (until late in the show's run) have the facilities to handle giant monsters, so unbeknownst to them, their comical-yet-mysterious teammate Jòji disappears on them, only to help them as Spectreman!

While the hero tries to convince him that his remarkable intelligence should be put at the service of good rather than be used for destruction and tyranny, Gori commits suicide after replying that he would rather die than live with such an inferior and self-destructive race as the humans.

Disguised as a human being (Jôji "George" Gamô), Spectreman requests his transformation from the unseen stern but benevolent Overlord of the Nebula Star, or is ordered by same to do so.

Saying "Ryōkai" (了解 - Japanese for "Roger"), or "Ready" in the US version, he raises his right hand towards the Nebula Star, which shoots a beam at him, transforming into Spectreman, a super-powered cyborg in a gold-and-copper cuirass, with a fin-topped full helmet with an angular metal face somewhat resembling the Rocketeer's signature headgear.

The entire 63-episode Spectreman series was dubbed into English and syndicated to television stations across North America, including Superstation TBS, starting in the fall of 1978 (more than seven years after the Japanese premiere).

[citation needed] Rather than being made of machinery, Leguman was made of vegetables with carrots for arms, pea pods for legs, a jack o'lantern pumpkin for a head, and a radish chest emblem on his leotard, and he engaged in brief inane low budget live action battles with bizarre robot monsters based on everyday items (vacuum cleaners, juicers, etc.)

[6] Spectreman is shown in the graphic novel The Arab of the Future by Riad Sattouf, as a Japanese TV show that the protagonist, as a kid, watches in Libya.