Hi guys, I'm looking for something I read like, back in 2013 or something. It was about a guy with a scary face who ends up getting some sort of spirit companion girl, they both enter an attraction park where people are doing some competition games for money.

A few things I remember, the protagonist starts using a chainsaw as a weapon at some point and works as a loanshark for the company of some woman. His first enemy is some kind of bulky military guy and it was a pretty funny comedy.

I thank you for any help!