A (エー, Ē) is a hero for the Neo Heroes and formerly a criminal with an A-Class level bounty placed on him by the Hero Association.[1]

He used to work as a hired assassin, but would also kill random people outside of his paid targets. His goal is to kill as many people as he can before he dies. He also serves as Fuzzy personal confidant who does many dirty works for the Neo Heroes.
Appearance
'A' is an average-looking man with a confident and slightly smug expression on his face. He wears large, round glasses and a dark shirt. His hair is medium-length, parted to the side, with smooth, voluminous strands brushed back, reaching past his ears for a sleek yet controlled look.
In the webcomic, he has quite messy hair.
Personality
'A' appears to be a calm and kind individual, as shown when he expressed concern for Kokou following the latter's unsuccessful attack on Suiryu, which resulted in Kokou being knocked back. However, given his reputation as a killer, this kindness could be a facade.

He claims that he does not take pleasure from murder; rather, he does it as a "game" to see how many people he can kill before dying. His cruel disposition repulses even fellow assassins like Speed-o'-Sound Sonic, who asserts that he is more rotten than the criminal underworld itself.[2] He is a sadistic and psychotic individual, completely indifferent to human life. Manipulative by nature, he is fully aware of the Neo Heroes' destructive plans to overthrow the Hero Association and control humanity through mind manipulation. He takes pride in violence, even boasting about using unusual methods to kill, which he views as trophies. 'A' believes human nature is inherently evil, reflecting his twisted, sadistic worldview.[3]
Plot
Neo Heroes Saga
Ninjas Arc
'A' is first introduced during the Neo Heroes leader meeting, where he asks Kokou if he is fine after the latter is knocked back by Suiryu. Following this, McCoy introduces him as an A-Class criminal specializing in monster techniques. Sekingar questions McCoy whether 'A' joined because the Neo Heroes will protect him from criminal prosecution, to which Child Emperor voices that if they can effectively control and make use of his abilities, it should be acceptable.

Neo Heroes Uprising Arc
Later on, 'A' is seen easily defeating a horned monster. Double Hole and Feather recognize him as a wanted criminal and attempt to accost him, but 'A' cryptically threatens them if they get any closer, stating that accidents happen during hero work.
During the robot invasion, McCoy approaches Metal Bat, who is in isolation due to suspicions of being a spy. McCoy informs Metal Bat about the situation, and Metal Bat tells McCoy to bring his original metal bat to him for a breakout. When McCoy attempts to do so, 'A' stops him and accuses him of engaging in treacherous behavior that will not be tolerated. Ryumon then joins them, and 'A' informs him about McCoy's act of treason, leading them to escort McCoy to Fuzzy for questioning.
Abilities and Powers
'A' is an effective fighter, earning himself an A-Class bounty and being noted by McCoy to have a fighting style specially suited for monster killing.

His Neo Hero suit significantly increases his already impressive power, allowing him to kill a horned monster with relative ease. However when fighting S-Class criminal Speed-o'-Sound Sonic, he and his Neo Hero comrades were completely outclassed.
Fighting Style
Hand-to-Hand Combatant: "A" is a skilled hand-to-hand combatant with great knowledge of human anatomy, which allows him to manipulate joints and cause significant damage to his opponents. This was evident during his fight with Ryumon, where he inflicted severe injuries even without activating his battle suit. Although he is slightly less strong and forceful than a professional athlete, he is still agile and effective at dodging blows, most of Ryumon's punches missed him, with only one landing. In terms of violence, "A" follows a methodology he refers to as "organized violence". This has helped him learn to kill in highly unusual ways, such as using chopsticks, lotion, water bottles, and even a laundry basket as improvised weapons, demonstrating his creativity and resourcefulness in combat.

Equipment
Battle Suit: 'A' wears a Neo Heroes battle suit, which provides him with a variety of functions.
- Mobility Analysis: The suit analyzes A's nervous system and body, with its synthetic muscle reacting accordingly and enhancing his physical abilities.
- Life Support System: The suit contains a life support system, although it can be damaged beyond function.
Bladed Staff: 'A' wields a staff with two blades perpendicular to the shaft on one side.[4]
Remote-detonated bombs: 'A' uses several remote-detonated bombs during battle to defeat his enemy or escape.[5]
Trivia
- In A's first manga debut as a silhouette in Chapter 190, his hair appeared very spiky and messy, resembling his depiction in the webcomic. However, when his full face is revealed in Chapter 205, his hair is smooth and slicked to the side, showing that Murata changed his design choice for A's hairstyle.