Outbound is a novel series written by Ryu Hidetaka. The story revolves around Naoya Koji, a famed gangster who was killed from a gunshot to the liver. Or so they thought. He survived the gunshot. However, instead of taking revenge, he decided to lay low to live a quiet, peaceful life. Until one day, his peaceful life is disrupted when former enemies and colleagues from his gang days comes after learning that he is alive, seeking revenge. Naoya has to stand his ground against all odds and use his remarkable skills to face variety of oppositions.