Kid Muscle is aggressively stupid in the best way, a show that treats intergalactic wrestling tournaments with the same deadpan sincerity as actual stakes. The comedy comes from watching this greasy idiot stumble into genuine heroism, his transformation sequences undercut by how much he sweats and complains the entire time. It's Kinnikuman but dumber, faster, and somehow more fun because it never pretends the premise makes sense.

Mantaro Kinniku, the 59th prince of Planet Kinniku, is lazy, immature and cowardly, and nothing like his heroic father, the famed wrestler King Suguru. Years after the original Kinnikuman, a powerful band of cheating wrestlers from space called dMp threatens the Earth. With the King nowhere to be found, a plan forms for his son to take his place. Mantaro wants no part of it and runs away to Earth. There he meets Meat, his father's old trainer, who sees King Suguru in the prince and believes he can be set on the right path. Mantaro must join the Muscle League, a group of wrestlers training to defend the planet, and chase Ultimate Muscle, a hidden power that makes him an almost unbeatable opponent. The result is a comedic sci-fi wrestling action series about a reluctant hero learning to better himself.