One Punch Man has speedily become one of the most popular anime and manga series worldwide, and that's largely due to its expressive main character Saitama.

But how did Saitama get his patented look and personality?

In an interview for Yamada Reiji’s Young Sunday, ONE, series creator of One Punch Man, broke down his thought process for Saitama's creation. Starting with Saitama's crazy strength, ONE explains that he "wanted to differentiate the character from pre-existing characters" and "thought it might be interesting if 'the first chapter is like the final chapter'; have the protagonist be extremely strong from the very start — be at the maximum power level which could only be attained in the final chapter of usual manga."

In terms of whether or not giving Saitama such strength would be difficult to write for, ONE countered with "there are manga protagonists that overcome hardships and complications by using their knowledge and experiences" but he couldn't "write that sort of character" and would rather "have the protagonist solve problems by punching."

But to balance how Saitama's strength with the necessity to create character drama, ONE made regular facets of like harder for Saitama to adjust to, "punching is oftentimes pretty useless against life’s problems. But inside One Punch Man’s universe, I made Saitama a sort of guy who was capable of adapting his life to the world that surrounded him, only armed with his immense power. The only obstacles he faces are mundane things, like running short of money."

ONE's balance of Saitama's incredible, fantastical strength with his focus on life's little foibles balance to create both a humorous and compelling main character fans want to see succeed.

For those unfamiliar with One Punch Man, the series follow Saitama, a regular working Joe who one day puts a stop to a violent villain attack. After this fight Saitama is inspired to become a hero. Training his body hard everyday, he's eventually granted with extreme strength. Looking for a worthy opponent, Saitama joins the Hero Association in the hopes of fighting them. But every fight he gets into ends after a single punch!

One Punch Man started life as a webcomic by series creator ONE in 2009. After going viral, surpassing seven million hits in June 2012, illustrator Yusuke Murata approached ONE about redrawing the series for a release in Shuiesha's Weekly Young Jump spin-off webcomics. Thirteen volumes of the series have been released as of this date.

VIZ Media bought the rights to distribute the manga in English, and the series was later adapted into a 12 episode anime series from Madhouse. The series first aired in Japan in 2015, and later debuted its English language broadcast on Adult Swim's Toonami block in 2016.