Reddit reviews One-Punch Man, Vol. 1 (1)

The licensed English version is from VIZ Media. The free versions you've been reading online are scanned from Japanese sources, cleaned up in Photoshop, and fan translated (known as scanlations).

Well there's manga's for some of those shows, supposedly Keijo!!!!'s manga is better than the anime but boy is it ecchi (almost porn but not quite), and I can't believe I forgot about One Punch Man it's anime and it's manga. If you end up liking OPM I'd also suggest checking out Mob Psycho 100 same artist/writer.

Viz is releasing it in English. You can probably find it in the manga section of your local bookstore or you can find it on online retailers like amazon here.

Amazon link

Uh, the one you found on Amazon in English isn't going to be ONE's webcomic. That's just a webcomic that's online for free. They're all written by ONE because ONE is the one who writes all of it. You aren't going to find OPM not written by ONE.

https://www.amazon.com/One-Punch-Man-Vol-1-ONE/dp/1421585642/ref=sr_1_3?s=books&ie=UTF8&qid=1500649751&sr=1-3&keywords=one+punch+man

This is what you're looking for.

One-Punch Man 1 price matched on Amazon, if no one's bought it yet...

Amazon seems pretty cheap

Amazon sells them but if you want to get it in person I get mine from Chapters/Indigo but I'm not sure if you live near one.