Four years ago, a group of three friends used to drink together at a bar called Lupin's. These three men: Dazai, Sakanosuke Oda, and Ango Sakaguchi, were members of the Port Mafia, when Dazai was a feared executive, Oda a low-ranking member known for hardly ever killing others with his gun, and Ango an intelligence officer. However, these days are soon torn apart, with only a photograph to remember this soon after, as Ango disappears mysteriously and Oda is sent to find him...