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?!

In order to avoid expulsion from the JCC, a young Sakamoto, Nagumo, and Akao are assigned a special mission--along with another outcast, Uzuki. Their target to assassinate is located at a special department store for hit men, but unbeknownst to them, their actions there will alter the course of their futures forever...