Katsura infiltrates the Shinsengumi as a prolific Afro-wearing swordsman. He greatly impresses the Shinsengumi trio as well as the Third Captain, Saitou Shimura. As Katsura tries to figure out his 'superior', Saitou sends a job request to the Yorozuya. And things begin to snowball from there.
A new recruit easily defeats thirty other potentials, impressing the Shinsengumi members, including Kondou and Hijikata. The Vice-commander gives the man's name as Hashira Afuro, but the man, Katsura wearing a large afro wig, nearly reveals himself by saying his catchphrase. He is saved by Okita demanding his chance for a match with him. The First Captain is stopped by a mysterious figure, surprising everyone. Okita tells Katsura that this person, more terrifying than him, would let the disguised patriot join his Third Squad if he can defeat the figure, the Third Captain Saitou Shimura. The next day shows a beaten up Katsura talking to the Yorozuya in their living room after telling them his plan of Shinsengumi infiltration. The trio mocks him for failing but he reveals that because they fought to a draw, Katsura has now become the Vice-Captain under Saitou. From what he learned, Saitou barely talks, has a habit of sleeping while standing up, and goes to the bathroom a lot. Saitou is also the only member of the 'silent unit' because his task is to bring potential Shinsengumi traitors into his unit and judge them, killing them if they are considered unworthy. The Yorozuya suspect that Katsura was already on thin ice but before continuing, Saitou is outside the apartment ringing the doorbell.
Gintoki tells Katsura to hide, but the Third Captain bursts through the window and searches around the apartment without saying a word. Growing annoyed by the silent treatment, Gintoki demands Saitou to leave. Saitou instead uses the bathroom and leaves, also leaving behind a job request. Katsura also leaves as well. The letter reveals that Saitou was cripplingly shy and his nervousness causes frequent stomach cramps. His 'silent nature' ironically made him perfect for investigations and he was forced to resort to writing in a diary for speech. The people on his list were actually potential friends who, when learning of the list, thought too much into it and fled in fear, making Saitou have no choice but to cut them down. He despaired over no longer making friends until Katsura arrived, the first person refusing to flee from him. He asks for the Yorozuya's help to muster up the courage to talk to him. The trio decide to help.
Saitou reads a letter from Gintoki that gives him pointers on how to slowly work his way to actual conversations. It is first tested on Katsura as he gives the captain (poisoned) tea. It fails as Saitou's (creepy) smile and (creepy) injuries scares Katsura into believing that Saitou knew the tea was poisoned after the captain destroys it. When the Yorozuya receives a letter stating that Saitou's 'smiles were scaring more people, Gintoki returns a letter telling the silent man the next phase. Saitou asks Katsura to follow him to a shed while the Yorozuya watches. It turns out that he held a tied Elizabeth. Angered, Katsura beats it up, pretending that it was a punching bag. In reality, Saitou had tamed Elizabeth as a pet, forsaking Katsura. In despair, Katsura flees. Gintoki realizes that Saitou and Katsura can never be friends and that this may finish Katsura's plans on internally destroying the Shinsengumi.
... Except one month later shows Katsura in charge of an Afro-wig-wearing Third Squad attacking terrorists.
- Katsura Kotarou (Main Antagonist)
- Kondou Isao
- Hijikata Toushirou
- Okita Sougo
- Saitou Shimaru (debut)
- Sakata Gintoki
- Shimura Shinpachi