Satsudou is a Manga/Manhwa/Manhua in english language, ACTION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Akamori Rokuo wants to be an ordinary salaryman but... He is a genius murderer born into a family that has been practising the ancient art of killing for centuries. Akamori faces obstacles like Yakuza, fighters and gangs in the path that goes to his want.