License-less Rider, legally named Satoru but operating as Mumen Rider, is the C-Class Rank 1 professional hero for the Hero Association in Z-City. He appears as a young man of average height and build, typically wearing brown torso and shoulder armor over a black leather suit, plus black gauntlets, kneepads, a green bicycle helmet, and dark-shaded goggles. His short brown hair and oval glasses remain hidden under his helmet during heroics. His primary transport is the standard utility bicycle "Bicycle of Justice" or "Justice," featuring a front light and handlebar basket. He employs a "Riding-Out-of-the-Saddle Mode" for higher speeds by standing while pedaling. Mumen Rider embodies unwavering courage, selflessness, and an unyielding commitment to justice. He consistently confronts threats regardless of personal risk, driven by the belief that heroism demands action even when victory seems impossible. This conviction explains his refusal to advance to B-Class despite holding the top C-Class rank for over half a year; he openly acknowledges his physical limits and feels undeserving of higher status. His humility includes deep respect for other heroes, especially those who save him, leading him to mail Saitama a simple "Thank you!!" letter and request a restaurant owner serve Saitama premium food after the Deep Sea King incident. While often underestimated by higher-ranked heroes, he disregards criticism unless it involves protecting civilians or upholding heroic ideals. He shows perceptiveness about others' capabilities, notably recognizing Saitama's true strength early on. His background traces to preteen years when he attended the same middle school as Saitama, though neither recalled this later. During this time, he used the self-styled name "Name-less Bicycle Commuter" and tried to stop delinquents extorting students, resulting in a beating. After Saitama defeated Crablante, Satoru applied to the new Hero Association and was assigned to C-Class. Consistent acts like retrieving a child's balloon or confronting criminals gradually elevated him to C-Class Rank 1. His plot involvement spans multiple conflicts. In the Paradise Group Arc, he confronted Hammerhead's gang to protect citizens but was instantly incapacitated. During the Sea Monster Arc, he raced to J-City against the Deep Sea King, intervening to save Genos from a fatal blow. He declared his resolve in a monologue: "Nobody expects much from me... but I must fight you anyway... It’s not about winning or losing! It’s about me taking you on right here, right now!" His repeated, futile assaults stalled the Deep Sea King until Saitama arrived, stirring civilian onlookers and earning Saitama's respect. He later thanked Saitama at an oden shop. In the Alien Conquerors Arc, he participated in A-City rescue operations with heroes like Stinger and Lightning Max. The Human Monster Saga saw him targeted by Garou during the Hero Hunt Arc. He attempted to engage Garou but was halted by the Tank Topper Army. When Tanktop Master prepared to execute a defeated Garou, Mumen Rider intervened, arguing excessive brutality would tarnish the Hero Association. He was swiftly overpowered by Garou afterward. Hospitalized with Tanktop Master, he discussed Garou's abilities with Saitama. Later, in the Super Fight Arc, he defended patients from hospital-invading monsters and narrowly survived Gyoffrey's attack due to Tanktop Master's intervention. Mumen Rider's combat abilities prioritize endurance and willpower over physical strength. His Hero Association ratings are: Justice (10), Popularity (7), Effectiveness (6), Stamina (4), Intelligence (4), Endurance (4), Power (3), and Fighting Ability (3). He withstands severe punishment, surviving repeated head trauma from foes like the Deep Sea King and Garou. His fighting style uses hand-to-hand combat and bicycle-assisted charges, though often ineffective against stronger opponents. Documented techniques include the direct tackle "Justice Tackle" and "Justice Crash," where he hurls his bicycle as a projectile. His defining trait is an indomitable will, enabling him to persevere through critical injuries to protect others or buy time. His relationships feature mutual respect with Saitama, who called him a "true hero" after the Deep Sea King battle. He maintains cordial ties with heroes like Tanktop Master, whom he aided during the hospital attack. Despite his low rank, citizens and colleagues admire his dedication, contrasting sharply with his self-assessment of inadequacy.