Embodiment of the Assassin in the Murim World

No.1 Killer Kim Gun falls into the world of Murim due to a mysterious accident
In order to return to the Earth from which he came from, he learns that he must complete the mission of "conquering Murim".

With two guns, Kim Gun's adventure to settle the unfamiliar world of Murim begins.

(Please note the title is a wordplay on 俠客/협객 which is what most martial artists would be referred to by normal people but they replaced 협 with the word 'gun'.)