Roppen 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

Six of the deadliest assassins battle to kill each other!

The stage is set in the "dictatorship" Rokugen Island, located in the western part of Yamaguchi Prefecture. There, the "battle of the six assassins" for the country's top position is about to take place...!

Will Sifu, a hitman-slayer who has been commissioned to participate in the battle, be able to survive this extreme survival?