The Split-Chinned Kid is the young grandson of Agoni, the multi-millionaire who would go on to found the Hero Association. Despite his brief appearance, he's one of the most quietly influential characters in the series: three years before the story begins, his mischief — drawing nipples on the sleeping monster Crablante with a permanent marker — provoked it into hunting him down.
Saitama, still an unemployed civilian with no powers at the time, initially decided the boy's problem wasn't his business and started to walk away, only to turn back and fight off Crablante when it attacked. That single act of intervention is what set Saitama on the path to training seriously and becoming a hero, and it's also what drove a grateful Agoni to found the Hero Association in the first place.
A young boy of average build with short dark hair in a neat bowl cut. His defining feature is a prominent cleft chin, split into two rounded lobes. Seen wearing a light t-shirt, dark shorts, and white sneakers, carrying a soccer ball.
A fairly typical, mischievous child, fearless (or naive) enough to prank a sleeping monster. After being saved, he’s moved enough by the experience to tell his grandfather the full story out of gratitude — a small act that ends up reshaping the world.
Lived in the era before the Hero Association existed, when monster attacks were rising with no organized response. Three years before the main story, he found the monster Crablante asleep on a park bench and drew nipples on its shell with a permanent marker.
Crablante wakes up and hunts the boy in revenge for the prank; he begs a struggling job-hunter (Saitama) for help. Saitama, despite taking a beating, uses his necktie to pull the monster’s organs out through its eye socket to save him. The boy tells his grandfather Agoni about the anonymous passerby who saved him — and Agoni, moved by the story, founds the Hero Association to find and fund people like that.
None — an ordinary child, notably skilled enough with a marker to draw on a sleeping monster without waking it.
vs. Crabrante — Ch. 2
Targeted for death over a childish prank and cornered in a park by the crab-like monster. Saved at the last second by Saitama — the fight that set Saitama's entire path as a hero in motion, and with it, the eventual founding of the Hero Association.
Major: Ch. 2. Mentioned only: Ch. 15 (as Agoni’s grandson).
Agoni (grandfather): his guardian, whose love for him became the financial engine behind the entire Hero Association. Saitama: the boy sees him as his hero, though it’s unclear if he ever connects that memory to Saitama’s current "Bald Cape" identity. Crablante: the monster that nearly killed him.
“He was asleep in the park, so I drew nipples on him with a marker.”
His cleft chin is an exaggerated echo of grandfather Agoni’s own chin. Despite having under ten lines total, he’s arguably one of the most narratively influential characters in the series — his rescue is the founding event of the entire hero system.
🇯🇵 Japanese Voice Actors
Naitou, Ami
🇯🇵 Japanese
🇺🇸 English Voice Actors
Taylor, Julie Ann
🇺🇸 English