It is a race against time before Isaburo kills Kondo while Gintoki and Okita fight Oboro and Nobume. Yet an event in the past brings everything to light in the present and it involves the Roshigumi, Isaboro and the Naraku.
In a flashback, mohawk punk Yamazaki tried to threaten Isaburo outside the Roshigumi doors but is harshly reprimanded by Hijikata. Isaburo is surprised to see that within days the ronin has become an organized force thanks to Kondo Isao. Later that day, Matsurdaira sneaks up on Isaburo as he struggles to respond to his pregnant wife's mocking emails. His newlywed wife was staying at her parents and approaching her due date so Isaburo had decided to try to communicate to her through mail, even though he was inept at it. The two samurai were meeting at an inn to discuss the Sada Sada's administration's plans for the developing Roshigumi police force. They will make them an official force, with their first assignment as bodyguards for the young Nobu Nobu and his father. In reality, they would be ambushed and forced to take responsibility and commit seppuku. Matsudaira greatly dislikes the plan and Isaburo admits that the Roshigumi were sacrificial pawns to get rid of Sada Sada's enemies. The commissioner sees the irony of how the two samurai nobles, with their samurai titles, were too cowardly to do anything samurai-like while the Roshigumi, lower-class ronin, were more samurai-like than the actual samurai. He told Isaburo that it will be tough to raise a child in this new era as a samurai or a father, but at least answer his wife's emails.
Days later, Okita wonders what new name their group should change to as he, Kondo, and Hijikata walk along a river bank. Kondo is happy that their countryside group had made it so far. They are interrupted by Isaburo sitting on the bank, struggling to figure out a name for his child. He is confused and unsure about how to raise his child in this new era and asked the trio what kind of samurai they want to be. Kondo is unsure himself and knows that there may be no answer even when they die. But he believes that there is no true way to be a samurai; one's journey of struggles and self-doubt was what makes someone a samurai, the only thing one can do is to continue searching and struggling as they move forward (he also gives this same speech to his men). He reveals to the Roshigumi their new name, Shinsengumi.
In the present, as Hijikata's group tries to reach their leader and Kondo and the injured Katsura try to flee the Mimawarigumi, Isaburo is still impressed by Kondo's unique charisma. He shoots and Kondo tries to block the bullet, but it reflects and slices his leg. The two injured men struggle to fight off the white-clothed officers. Kondo is forced to stop when he sees a group of Mimawarigumi dragging an unconscious Matsudaira in front of him. As Isaburo prepares to shoot Kondo, Matsudaira lets out a smile, as the "Mimawarigumi" officers around him suddenly attack their comrades. Barreling through the officers to attack Isaburo was Hijikata. Isaburo's gun is destroyed by Saito and Elizabeth reaches Katsura. Both Matsudaira and Hijikata mock Isaburo for being a bad commissioner, and Isaburo realizes that the Shinsengumi saved Matsudaira and stolen the Mimawarigumi's clothes to trap Isaburo. The Shinsengumi make a protective wall around Kondo; he apologizes for putting his friends in danger, but Hijikata blames themselves as well; they ended up on the island even after all their agonizing, and are a long way from the "true path". He admits that they did not care what path they take as long as they have Kondo with them. Touched, he tells his men to fight and they clash with their white clad counterparts, with Hijikata and Isaburo continuing their fight.
Meanwhile, at the cliffs, the remaining Shinsengumi and Jouishishi, as well as the Yorozuya continue fighting, with the biggest fights being Gintoki vs Oboru and Okita vs Nobume respectively. After their finishing strike that lead to Okita being cut in the arm and Nobume's smaller sword destroyed, Nobume wonders in despair why everyone was going against Isaburo. Back in the past, Isaburo meets with an organizer and is introduced to a group of children, trained by the Naraku, who will be involved in the assassination plot. One of these children is a prodigy, Mukuro (the young Nobume). Isaburo is uneasy about using children but Mukuro chastises him for having strayed off the right path, just like her, while offering him a doughnut. In the present, Oboro and Nobume interrupt their fights with Gintoki and Okita to reveal the truth behind Isaburo's plans.
In the past, the plan was to have the child assassins attack the unsuspecting Shinsengumi and kill the Hitotsubashi father and son. Isaburo watches from a distance as the retainers and the carriage take a break in a shrine. Kondo was happy about their first mission and wanted it to be successful. They are interrupted by a ball accidentally thrown by children. Before being turned away, one of the boys reveals that there were men hidden, surrounding the group. Hijikata and Kondo tell some of their men to check their surroundings and are horrified to see the same boy running towards the carriage, realizing that they will be too late to stop the child from attacking the officers' charge ... until the child shows that he held an erotic manga and gave it to the Hitotsubashi elder, stumping the Shinsengumi. The child reveals someone (Isaburo) had asked him to deliver the magazine, and the group is attacked by the Jouishishi. The person who was truly inside the carriage was Matsudaira, following the plan created by Isaburo, who had leaked information to the rebels, foiling the assassination as well as raising the Shinsengumi's standing. As he learns that his wife gave birth to a girl and wonders what he will name her, unbeknownst to him, he was being watched by the Naraku.
Okita is surprised by the revelation that Isaburo saved them. Nobume adds that he was also trying to save the children as well, but betraying the Naraku came with a price. In the past during the night, Isaburo rushes into a village, desperately trying but failing to send an email to his wife. He is confronted with the carnage of dead bodies, which includes his wife and child; the only survivor was the blood-drenched assassin, Mukuro. The failed email was that he had decided to give his daughter the name...Nobume. Enraged, he attacks the unresistant Mukuro. In the present, Oboro and Nobume reveal that neither Isaburo and Nobume killed each other. Mukuro, due to the influence of Shouyou's teachings, decided that Isaburo deserves to kill her. Isaburo refuses, deciding that he will destroy this brutal era that lead to this moment, including himself, and he will force Mukuro to help him achieve this goal, ending with her killing him. Oboro tells Gintoki that Isaburo had purposely fanned the flames of rebellion by influencing a few of the events in this series, but the Naraku was aware of his plans and, arriving in airships, attacked the forest, injuring many of the men including Isaburo and Hijikata. Hijikata wonders what's happening but Isaburo flippantly responds to the vice-chief that he will deal with the assassins first before finishing their fight. He emails his hidden ships to attack the Naraku ships.
Back at the cliffs, Okita watches as a few Naraku ships land and the assassins disembarked, attacking everyone, while fending off Nobume's attacks. Nobume starts to think about her duty to kill Isaburo, after taking away everything from him but forcing him to live on with the pain. But despite her determination to kill him, she begins to unknowingly shed tears as she attack Okita, causing the first captain to hesitate. The two are suddenly stopped and held in place by Kagura, who tells them they have done enough.
- Tenshouin Naraku
- Sakata Gintoki
- Shimura Shinpachi
- Tokugawa Sada Sada (mention)
- Hitotsubashi Nobu Nobu (mention)
- Yoshida Shouyou (mention)
- Okita Mitsuba (cameo)