Dokuro (2002) 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.nl fastest updating comic site. The Summary is

His real name is Kikuchi Takeo. Code name: Dokuro.

Abandoned by own mother to die in a fire, he survived and made it out as an assassin for an underground group.