One Punch Man Trivia

  • Acting for Two: Daisuke Namikawa voiced Dr. Genus and Pig God.
  • All-Star Cast: The voice acting credits are basically a roll call of anime's top Japanese voice actors - even one-episode characters are voiced by heavy hitters such as Miyuki Sawashiro (Mosquito Girl) and Unshō Ishizuka (Asura Rhino). This also applies to the production of the anime, with big names in the industry working alongside Madhouse's in-house staff for most of the episodes. The English cast is no slouch, either, bringing together voice actors from not only Bang Zoom's stable, but also Texas, including Funimation's Christopher Sabat and Mike McFarland.


  • Vaccineman in the Japanese version is voiced by Ryusei Nakao, who voices Baikinman from Anpanman, the character who Vaccineman took his inspiration for his name from. The dub just cuts straight to the chase and cast Piccolo himself.
  • In the dub, the Beast King is voiced by Paul St. Peter (who voiced Leomon).
  • This isn't the first time either Bryce Papenbrook (English) or Miguel Angel Leal (Latin American Spanish) can change into a titan.
  • This isn't the first time Jamieson Price has been an intelligent robot warrior, though he's upgraded from a cyborg to a robot drone controlled by a scientist.
  • Saitama is voiced by Makoto Furukawa, who later got the role as one of the most famous mythological Invincible Hero Achilles
  • The French dub casts rapper Orelsan as the voice of Saitama. Outside of acting, his music portfolio is known for carrying some pop-culture referenced songs, making his role fitting for the character.
  • Yusuke Murata's favorite characters are Boros and the Deep Sea King because of how much of an impact they've had on the world. ONE's favorite characters are Saitama, King, and the Deep Sea King.
  • Murata has stated he dislikes Sweet Mask. Because of this, he tries to draw him as handsome as possible to get over his feelings.
  • The Esper sisters Tatsumaki and Fubuki are both 28 years old and 23 years old respectfully, but their Japanese voice actors are not. Aoi Yūki, Tatsumaki's voice actress, is a year younger than Saori Hayami, Fubuki's voice actress. This is even more notable in the Latin American Spanish dub, as Tatsumaki's voice actress, Azul Valadez, was 21 years old when she voiced her.
  • One of the main reasons that the first season, an anime with an average budget, has such beautiful animation. While the second season's animation suffered due to the studio change, some of animator Kenichiro Aoki's best work is in the series just because he loves it.
  • With My Hero Academia. Ironically, both shows and their English dubs are also distributed in the U.S. by rival companies, with One-Punch Man distributed by Viz Media and dubbed by Bang Zoom! Entertainment, while My Hero Academia is dubbed in-house and distributed by Funimation.
  • There's a rumor floating around that ONE said Saitama's Serious Punch is half the strength of the Big Bang, and that he could easily destroy the entire universe with only his punches. No records of ONE saying this exists.
  • Yusuke Murata himself. He loved ONE's work on One-Punch Man before talks even began for the manga adaptation; after a near-death experience due to a respiratory issue, Murata decided that he wanted to collaborate with ONE at least once before the end of his life. Fortunately, he recovered and the two are now an impressive team.
  • Zach Aguilar, a self-professed fan of the webcomic, joins the English dub cast.
  • Max Mittelman and Zach Aguilar as Saitama and Genos. Here, they are allies, unlike their roles in Aldnoah.Zero as Inaho Kaizuka and Slaine Troyard, where they are enemies.
  • An internal version occurs between adaptations. In the webcomic and manga, Saitama and Genos' mail is air-dropped because of how dangerous City Z is; in the anime, it's delivered via drone instead.
  • While season two of the anime didn't turn out completely terrible, many fans were disappointed by its animation, sound direction, and pacing. A lot of this was due to the studio change forcing JC Staff to suddenly stuff One-Punch Man in between several other shows that were also in the works, leading to a lot of priorities changing and production being rushed. If one is to look at JC Staff's other works at the time such as A Certain Scientific Railgun T, the production is much cleaner and the animation much prettier.
  • Originally Boros had a much different design, appearing less like an alien and more like a generic one-eyed Bishōnen in demonic black armor. Later, during his fight with Saitama, Boros broke off one of the ship's fins and threw it at Saitama, nearly bisecting the entire spacecraft in the process. This was all redrawn, making him look more alien and swapping out the fin-toss for the moon-kick. There was also a plan for a flipbook animation of Bang hurtling through rubble after being hit by Melzargard, though it never got past the draft phase.
  • According to Murata, the energy balls used by Vaccine Man, Homeless Emperor, and Choze are all made of the same kind of energy.
  • Murata revealed what ethnicities certain characters would be in the real world: Genos would be German, Tatsumaki and Fubuki would be French, King would be American, Sweet Mask would be Korean, Suiryu would be Italian, and Choze would be Russian.
  • If Metal Bat were at the Monster Association raid, things would've gone very differently.
  • Murata said he doesn't know who'd win between Saitama and Goku.
  • Sonic would've been able to kill the Deep Sea King if he still had his weapons and if it didn't start raining. Also, Sonic and Genos are evenly matched and a fight would be inconclusive.
  • Murata said that Orochi is above Dragon-level but not God-level, similar to Boros. He also stated that Groribas, Melzargard, and Geryuganshoop wouldn't even come close to defeating him, even if they made plans beforehand and worked together.
  • ONE stated Golden Sperm is as powerful as Ossan from Makai no Ossan. Murata said that he's not sure who would win between him and Orochi, since Golden Sperm is much faster but Orochi is more skilled in martial arts.
  • The character design of Saitama is based on the gag anime superhero Anpanman from Soreike! Anpanman (1988).
  • Saitama's name comes from the Japanese province where the creator "ONE" used to live.
  • Lord Boros is the first villain in the series to survive Saitama's punch, giving the longest fight Saitama has ever encountered in the series.
  • Saitama is directly responsible for the creation of the Hero Association by saving the big chinned brat who is the grand child of the founder of the Hero Association. When the founder come to know of this incident he came up with the Hero Association system.
  • Murata made Saitama bald superhero cause he saw the world full of cool good looking heroes, and he believes that heroes coolness comes from their spirit not their looks.