An anime television adaptation by Madhouse aired in Japan between October and December 2015. It was dubbed in English during the summer of 2016, and later that year a planned second season was announced.
An anime adaptation was announced in the 15th issue of Weekly Young Jump on March 10, 2015. The series’ first season was directed by Shingo Natsume at Madhouse and written by Tomohiro Suzuki. The series also features character designs by Chikashi Kubota, who also serves as chief animation director, music by Makoto Miyazaki and art design by Shigemi Ikeda and Yukiko Maruyama. Ken Hashimoto serves as the series color key artist, Akane Fushihara is the director of photography and Kashiko Kimura serves as the series editor, and Shoji Hata does sound design. The opening theme song is “The Hero!! ~Ikareru Ken ni Honō o Tsukero~” (THE HERO!! ～怒れる拳に火をつけろ～, “The Hero!! Set Fire to the Furious Fist”) by JAM Project, and the closing theme is “Hoshi Yori Saki ni Mitsukete Ageru” (星より先に見つけてあげる, “I’ll Find It Before the Stars for You”) by Hiroko Moriguchi.
One-Punch Man‘s first season aired in Japan between October 5, 2015 and December 21, 2015 on TV Tokyo, airing at later dates on TVO, TVQ, KBS, BS Japan, and AT-X, and ran for 12 episodes. The season streamed on Niconico and was simulcast on Hulu, Daisuki, and Viz Media’s Neon Alley service. A preview screening was held in the Saitama City Cultural Center on September 6, 2015. The series is licensed by Viz Media in North America, and by Kaze UK in the United Kingdom. An original video animation was released with the tenth manga volume on December 4, 2015. Additional OVA episodes are included with Blu-ray Disc & DVD volumes of the season, the first of which was released on December 24, 2015. Murata announced in the last weeks of the first season’s airing schedule that he was working on making a second season a reality, but had not confirmed it was in development as of December 2015. A second season was later confirmed in September 2016 and is currently in production. Viz Media announced that they were working on an English-language dub of One-Punch Man at Anime Boston 2016. On July 1 of the same year, It was announced during Toonami’s Anime Expo panel that the series would begin airing on July 16, 2016.
The title character is a bald-headed 25-year-old man who has been bored of fighting because he is easily able to defeat enemies with a single punch. He lives in an apartment in City Z. Three years prior to the start of the series (and when he had hair) he was applying for jobs as a salaryman, where he defeats a crab-like monster that attempted to kill a child. He says he became a hero for the fun of it. Saitama’s abilities consist of superhuman speed, strength, stamina, and durability, which he attributes to a daily training regimen of 100 push-ups, 100 sit-ups, 100 squats and a 10 km run, eating right, and not using the air conditioner or heater to reinforce his mental fortitude. He enters the Hero Association at the lowest C-class tier and rank due to his miserable performance on the written exam and essay, but had broken all the records on the physical portion of the test. He soon advances from doing superheroic deeds, although many of his efforts are not fully recognized because of collateral damage or because he was working with other higher-tiered superheroes. He does not mind letting others have the credit though as demonstrated in his actions following the fight against the Deep Sea King. In the Dark Matter Thieves story arc, he is not bothered by the telekinesis user that throws rocks against him, and has one of the times where he has used his “serious punch”. He becomes friends with S-Class members Bang and King. He knows that King is physically not a superhero, but encourages King to continue projecting his public image of being one; he also visits King’s place and plays video games with him. His superhero name in the association is Bald Cape.
Genos is a 19-year-old cyborg who becomes Saitama’s disciple after bearing witness to Saitama’s easy victory over Mosquito Girl. Four years prior to the start of the story line, his family was killed by a rampaging cyborg. Genos was nearly killed in the attack and his body was destroyed so, to keep him alive to stop the rampaging cyborg for justice, a scientist named Dr. Kuseno took Genos in and modified his body to make him a cyborg with destructive capabilities. However, Genos remains steadfastly convinced that justice demanded vengeance against and destruction of the cyborg. His perfect score on the entrance exam for the Hero Association places him in S-Class, but he still considers Saitama to be his master and goes with him whenever he is not summoned to other missions. He lives with Saitama after offering a sizable down payment for his share of the rent. His superhero name in the Hero Association is Demon Cyborg