Taro Sakamoto was once a legendary hit man considered the greatest of all time. Bad guys feared him! Assassins revered him! But then one day he quit, got married, and had a baby. He's now living the quiet life as the owner of a neighborhood store, but how long can Sakamoto enjoy his days of retirement before his past catches up to him?!

When Slur takes what should be a lethal wound, he transforms...suddenly manifesting Akao's personality? Sakamoto and Nagumo are baffled to encounter what seems to be their long-lost friend, and the trio attempts to flee from the JAA. But when they come face-to-face with their most dreaded opponent, the Assassin Exhibition of the Century reaches its climax!