Shamo

Shamo (軍鶏; "Gamecock") is a Japanese manga series written by Akio Tanaka [ja] and Izo Hashimoto[a] and illustrated by Tanaka. It was first serialized in Futabasha's seinen manga Weekly Manga Action from 1998 to 2003 and moved to Evening in 2004. It was discontinued in 2007 due to creative differences but returned in 2011 and ended in 2015. It tells a story of a boy who killed his parents and turned himself into a cold-blooded martial artist. The manga inspired a Hong Kong film adaptation released in 2007.