Hero Name: Caped Baldy. He lives in extreme poverty. He is the overwhelmingly strongest being in his universe. It is highly likely that even if every character except God attacked him at once, they wouldn't stand a chance. The wind pressure from a normal punch alone is enough to easily blow away an entire mountain. While his physical capabilities have reached a level no one can touch, his knowledge and intelligence are nothing special. Before meeting Genos, he was so out of touch with the world that he didn't even know the Hero Association existed. When he joined the Association, he ranked 1st in the physical exam with overwhelming scores, but because of his terrible writing and essay skills, he botched the written exam and was placed in C-Class. In truth, his ignorance of worldly affairs is not a matter of intelligence, but rather a lack of interest and a tendency to find gathering information bothersome. He is always relaxed. He is bald. He is Genos's master.

A cyborg with a serious and stoic personality, almost always expressionless. Boosters: Thrusters located on both shoulders. He can increase his speed through these boosters and achieve limited flight by linking them with the Incineration Cannons in his arms. Cyborg Legs: Genos's legs. Built with a sturdy structure to withstand high-speed movement, they are equipped with shock absorbers to minimize the time taken to transition to the next move after landing. Unlike his arms, they are not equipped with specific weapons. He possesses a search function recorded in the official Hero Encyclopedia that automatically detects biological signatures and high-speed approach reactions within range. Machine Gun Blow: A technique where he delivers a barrage of punches at incredible speed using the thrusters in both elbows. S-Class Rank 14, known as Demon Cyborg. He serves Saitama as his master and lives with him.

Though she looks like a child, she is 28 years old. A hero with green hair curled at the tips. Like her sister, she is beautiful but has sharp eyes and usually wears a tight-fitting dark dress. She uses psychokinesis. S-Class Rank 2, Terrible Tornado. As an S-Class hero, she is extremely proud. She is highly competitive, short-tempered, and does things at her own pace. Even among the eccentric S-Class heroes, she stands out for her sharp tongue and sarcasm, and she never hesitates to use force. Her true power lies in her immense psychokinesis. Other psychokinetic characters in the series include Fubuki, Psykos, and Geryuganshoop; she easily overwhelms Fubuki, and even Psykos's psychokinesis, which other S-Class heroes couldn't handle, was useless against Tatsumaki. Furthermore, she can fly at ultra-high speeds using psychokinesis, and the mere act of her brushing past or landing can devastate the surrounding area.

The hero name 'King' was given to him to signify that he is the strongest. Befitting the strongest hero, his tall stature and intimidating expression create a truly terrifying impression, and his eyes always seem to radiate a murderous intent that dispatches opponents. However, he is actually a coward who rose to S-Class Rank 7 purely by luck. He has three scars over his left eye. He is close friends with Saitama and they play video games together. He is an ordinary, timid otaku with absolutely no combat abilities.

S-Class Rank 3. An elderly man with a very sharp overall impression, featuring upward-swept hair and a mustache. He runs a dojo at the top of a mountain and is a master of the martial art known as Water Stream Rock Smashing Fist.

Unlike her sister who has a child-like physique, she is a beauty with green eyes, a black bob cut, and a large bust. She is an A-Class hero in the Hero Association and the younger sister of S-Class Rank 2, Terrible Tornado, by five years. Together with her sister, they are called the 'Psychic Sisters,' but due to her appearance, many people in the world mistake Fubuki for the older sister. She uses psychokinesis, is the leader of the Blizzard Group, and is B-Class Rank 1.

Feeling that the 'victory of justice' established since childhood was a tragedy, he began his hero hunt with the goal of becoming the 'strongest monster who will never lose to anyone.' He once attended Silver Fang's dojo, but one day, deciding he had nothing left to learn, he beat up all the other disciples and was subsequently beaten by Bang and expelled.

Hero name 'Handsomely Masked Amai Mask.' Due to his handsome looks and his outwardly kind personality, he enjoys peak popularity alongside S-Class King. Looking at his activities in the series, he seems to be very active, filming dramas and appearing on various TV shows while performing hero duties. He usually works as a model, actor, and singer. A-Class Rank 1.

A boy who holds the position of S-Class Rank 5 at a very young age. Although he looks like an ordinary child, he primarily plays the role of supporting other heroes based on his brilliant brain, tactical planning, and command abilities. While the heroes introduced so far are strictly combatants, Child Emperor's aspects as a strategist and commander are more prominent.

Speed-o'-Sound Sonic. A ninja with incredible speed and strong combat power. He claims to be Saitama's rival but is always defeated. He is not a hero.