Homeland: Planet Kinniku, Age: 14 (Choujin Olympics: 15, Ultimate Tag: 16), Height: 176cm/5'9", Weight: 83kg/189lbs., Chojin Power: 930,000.
The story's protagonist and the 59th prince of Planet Muscle—son of the legendary first Kinnikuman, Suguru Muscle, and Belinda. Mantaro grew up privileged and sheltered, which made him a lazy, cowardly teenager. He's basically what his old man was like at the start of the original series, except way more chickenhearted. Matches usually see him panicking early on, scraping by on luck until something clicks—namely, when his friends are threatened or his opponent breaks the rules. That's when he taps into Kajiba no Kuso Djikara, his burning inner strength. His forehead lights up with the Niku-Mark, and suddenly his power, stamina, and technique skyrocket.
Here's the thing: Suguru had his entire record wiped years ago, so Mantaro had no idea his dad was basically a superhero until he ran into Alexandria Meat. The name "Mantaro" itself is a mashup of Ultraman Taro and the Kinniku legacy.
Early on, Mantaro leans hard on his father's signature finisher, the Kinniku Buster (the English dub awkwardly called it the Butt Buster, but it's really the Muscle Buster). He rides that move to tons of victories before developing his own ultimate technique: the Muscle Millennium. The kid's a bit of a horndog—constantly chasing after girls—but his real love interest is Rinko Nikaido. His go-to meal is a galbi bowl, which he's known to sing about on the regular.
In the Japanese version, Mantaro has this quirk where he replaces the standard masu suffix with "Muscle" instead. So "Itadaki-masu" (the phrase you say before eating) becomes "Itadaki-MUSCLE."
Content compiled by AnimeList.moe from publicly available sources.
