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.
Sakamoto's ex-colleague arrives with news of a one-billion-yen bounty on Sakamoto's head. For safety, Sakamoto takes his family to Sugar Park, where he must fend off assassination attempts while pretending to enjoy a fun day out.
With the poison-wielding hitman taken out, the Sakamotos head to their next attraction, where they're ambushed by Dondenkai Ltd's ultimate assassin duo.
A poverty stricken sniper, Heisuke Mashimo, hunts down Sakamoto for reputation and the reward bounty. However, not recognising Sakamoto's new form, he ends up joining a paintball competition with Sakamoto and Shin instead.
The battle between Taro Sakamoto and Kashima continues, as the legendary hit-man had the obvious upper hand. On the other hand, Shin continued his battle against Seba as Heisuke joined the battle, giving the them an upper hand.
The crew faces Wutang in a high-stakes casino showdown to learn who issued Sakamoto's bounty. Meanwhile, X sends a group of vicious assassins their way.
Revolves around Shin and Lu encountering Saw, a serial killer who seeks to give people exciting deaths. Meanwhile, The Order plans to eliminate the escaped death row inmates targeting Sakamoto.
Shin's evolving mind-reading helps him and Lu battle Saw. Lu's "Mafia Drunk" mode finishes Saw, who then gets killed by Hyo. Osaragi brutally defeats Dump. ending with Aoi seemingly in danger due to Slur's schemes.
The battles rage on even as the crew gets treated by Granny Miya. Minimalist threatens Aoi at the store while Heisuke clashes with Apart at Tokyo Tower.
As Apart reveals his past-unable to form human connections and seeking meaning through killing- Meanwhile, X is moving with a hidden agenda that could shake the assassin world to its core..
Sakamoto discovers the supposed threat from the death row inmates is just a distraction designed to lure the assassin group ORDER into a trap. The real objective of the antagonist X (Slur) is to destroy the Japan Assassin Association (JAA)
It's every assassin for themselves as the exam takes to the skies. While Sakamoto impresses fellow candidate Akira, Shin takes on the germaphobe Mafuyu.
Sakamoto discovers Akira's ties to an old friend. While Shin and Toramaru vie over their favorite assassin, X's secret plans throw the exam into chaos.