Mumen Rider, real name Satoru, is the Rank 1 C-Class hero of Z-City — the strongest hero in the weakest official class, and proof that rank in the Hero Association doesn't always track with raw power. He wears light armor over a black leather suit with gauntlets and kneepads, tops it off with a green bicycle helmet and dark shades, and fights almost entirely on and around his bicycle, using it as both transport and weapon in his signature Justice Crash charge.
What he lacks in superhuman ability he makes up for in sheer refusal to quit — he has thrown himself at the Deep Sea King and later at the Hero Hunter Garou with essentially no chance of winning, purely because backing down would mean leaving people undefended. Saitama, who treats most heroes with polite indifference, genuinely respects him: he complimented Mumen Rider's fight against the Deep Sea King, visited him in the hospital after Garou nearly killed him, and counts him as one of the few people who knows what Saitama's strength actually looks like. Mumen Rider's compassion extends even to his enemies — he's shown real sympathy for Garou, believing there's still a person worth saving underneath the violence.
A young man of average height and athletic build with short, messy brown hair. He wears a tan cycling helmet with a brown stripe, shaded goggles, an olive-drab armored chest plate bearing an “M” emblem, shoulder and elbow pads, and a black form-fitting bodysuit with knee pads and cycling shoes underneath. He’s rarely seen without his bicycle, “Justice.”
Given his fighting style, he’s frequently drawn mid-recovery — bandaged up or in a hospital gown.
Indomitable Will
He refuses to retreat no matter how outmatched he is, self-aware of his own weakness but convinced it’s his duty to keep fighting anyway.
Humble
He famously turned down a promotion to Class B, feeling he hadn’t yet earned the right to stand among stronger heroes.
Selfless and Polite
He consistently puts civilians’ safety over his own, and is well-mannered enough to hand-write Saitama a thank-you letter and later treat him to a meal.
Merciful, Even Toward Enemies
He tried to stop Tank-top Master from delivering a killing blow to Garou — because Garou was still human.
He has spent his entire hero career in Class C, becoming a local legend for consistent, dedicated community service, and is used in Hero Association training materials as an example of ideal conduct.
Reportedly attended the same middle school as Saitama (unconfirmed).
The Paradisers Incident (Ch. 12)
Tries to stop Hammerhead’s gang, is easily beaten, and is then credited by the media for their defeat anyway — to his embarrassment.
The Seafolk Invasion (Ch. 25–28)
The last hero standing at a civilian shelter against the Deep Sea King. He takes a brutal beating but refuses to stay down, buying time for Saitama to arrive and inspiring the public in the process.
Hero Hunter Arc (Ch. 47–48)
Intervenes to stop Tank-top Master from over-punishing Garou during a patrol encounter, and is himself targeted and hospitalized by Garou as a result.
Monster Association Raid (Ch. 136)
Still hospitalized when the massive monster outbreak hits, he checks himself out anyway, leaving a note on his pillow saying he’s going to help.
No Superhuman Abilities
His real strength is expert cycling and an extraordinary pain tolerance — he has survived direct hits from Demon- and even Dragon-level threats that would kill an average person.
Signature Moves
Stand-up Pedaling Mode (a high-speed sprint to reach incidents), Justice Tackle (a shoulder charge), and Justice Crash (using the bicycle itself as a blunt-force weapon).
Limitation: no superhuman powers at all — consistently outmatched by anything above Disaster Level: Wolf.
vs. Deep Sea King — Ch. 26–27
Fought a fight he had no business winning just to buy a shelter more time. Lost and was hospitalized, but stalled the monster long enough for Saitama to arrive.
vs. Garou — Ch. 47–48
Tried to mediate between the heroes and the Hero Hunter. Lost badly — his second major hospitalization, and proof Garou wasn't going to show anyone mercy.
Stopping Tanktop Master — Ch. 47
Threw himself between Tanktop Master and a killing blow on Garou. It worked — which ironically gave Garou the opening to counterattack.
Major appearances: Ch. 12, 25, 26, 27, 28, 47, 48, 136.
Minor appearances: Ch. 18, 38, 49, 59, 145, 148, 151, 153.
Mentioned only: Ch. 115, 141.
Saitama
A close ally and friend — one of the first heroes to recognize Saitama’s real character and quality beyond his low rank.
Tank-top Master
A fellow hero and hospital roommate after their respective beatings by Garou; the two share mutual respect.
Garou
The enemy who hospitalized him — and whom Mumen Rider still insists deserves treatment as a human being rather than summary execution.
A Class B hero named "Maruido Yankee" reportedly joined the profession specifically admiring Mumen Rider's spirit (unconfirmed).
“I am the Bicyclist for Justice... known as Mumen Rider!”
“I know that I’m weak! I know I have no chance of winning! But I have to do this anyway!”
“It’s not about winning or losing! It’s about me taking you on right here, right now!”
“He claims to be a monster... but he’s human.” — defending Garou
“Mumen” means “No License” in Japanese — his whole design is a parody of Kamen Rider (“Masked Rider”). Despite his low rank, he’s one of the most beloved heroes among children in-universe and a fixture of Hero Association guidebooks. He is reportedly strong enough to qualify for Class B but stays Class C Rank 1 by choice.
🇯🇵 Japanese Voice Actors
Nakamura, Yuuichi
🇯🇵 Japanese
🇺🇸 English Voice Actors
Daymond, Robbie
🇺🇸 English