Sakamoto enjoys a quiet life in retirement with his family. But one day, an old colleague demands he return to the assassin world — or face consequences.

While out on an errand, Sakamoto and Shin encounter Lu Shaotang, the daughter of a mafia boss, who's on the run and targeted by twin assassins.

After learning of the huge bounty on Sakamoto's head, the crew tries to enjoy a family outing at the amusement park while fending off assassins.

Sakamoto goes all out in a fierce one-on-one duel with Boiled. Meanwhile, ORDER members are tasked with handling a serial case targeting assassins.