Red Raven

Red Raven (レッドレイヴン) Is a shōnen manga series written and illustrated by Fujimoto Shinta. It was published between April 2010 and October 2013 in the magazine Monthly Shōnen Gangan, and has been compiled and published in a nine-volume book set. A French translation was published by Kana in July 2012

Plot
When the Raven starts to sing, people die... An unstable world, a weak government... and Mafia's escaping from their sins... In order to reduce unpunished crimes committed by the mafia... A Strength was born... Its agents are merciless and they kill withought hesitation. The Last Enforcement Organization known as Red Raven.