I know that he took inspiration from Mabinogi (cause I play it and recognize a large amount of the stuff in it, like gaining knowledge of Skills in Mabinogi). Plus Mabinogi is also a Korean game and The Gamer is a Korean Manga (or Manwha). 

Still though the element of the MCs getting the Gamer Ability is what makes this RP based off of the Manwha, plus I will also have some other elements from the Manwha as well (like the Gaia Theory and a few other small things). 

Still, its the Manwha that gave me the inspiration to make this RP. 

But yea, I get what you're saying. And don't worry, Mabinogi (which I just started to play again after several years of not playing it) has given me some ideas as well.