Ha Maru, a butcher working at a livestock company, is invited by his supervisor to go on a business trip to Japan. However, he soon discovers that the place he has been sent to is a criminal organization run by the Yakuza. In order to survive in this dangerous environment, Ha Maru struggles and gradually awakens his hidden talent for using knives. The butcher, who has now set foot in the underworld, challenges the pinnacle of the criminal world to stay alive. 413v65
Original Novel:
Munpia, Naver Series
Original Webtoon:
Naver Webtoon, Naver Series
37 Chapters (Ongoing)

This one is great. There's just one part I did not like.
I feel like it's too soon for the MC to defeat and kill that big axe wielding guy. The most the MC should've done was cut the dude's face, just to hit home the fact that the MC is actually extremely dangerous.
I also hate how they humanized that red headed bastard. Boo f-ing hoo. nah bro, you an animal. You don't deserve a sad backstory.