The No.1 Hitman, Kim Gun, finds himself plunged into the world of martial arts due to a mysterious accident. To return to his original world, he must complete a mission called 'Martial Arts Conquest.' With a total of 2 guns, Kim Gun's adventure to subdue the unfamiliar martial arts world begins.(Source: Naver, translated)
— Description from AniList community (anilist.co).
