"Our Shinsengumi... protect it. Please."

Returning to Edo and the Shinsengumi Headquarters is the Shinsengumi's advisor, Itou Kamotarou. Only having joined a year ago, he is strong in managing political matters and has managed to return with a collection of weapons for everyone to use, much to Kondou's surprise. However, little do the men know that alongside the swords Itou has returned with he also has ambitious plans for taking the Shinsengumi in a new direction.

While the rest of the Shinsengumi is preoccupied with new-fangled swords that play music or have floor-cleaning attachments, Hijikata is headed to hand his old sword over for repair. Ignoring the warnings of the swordsmith, Hijikata grabs a supposedly "cursed" sword off of the wall to borrow while his is being fixed. Unfortunately for him, this decision, along with Itou's arrival, would be the start of what slowly begins to unravel the close ties between the members of the Shinsengumi.

"Some time in the future, I'll kill you."

As Hijikata steps outside of the store, he is approached by a number of Jouishishi members who begin threatening his life. As he begins to take out his sword to attack, it comes to a surprise to him when he loses control of his body and finds himself on his hands and knees, begging them to spare his life. The Jouishishi are shocked that the fearsome "demonic vice commander" is acting in such a strange manner, but they're full prepared to take advantage of it. However, just in the nick of time Itou comes and fends off the members of the faction. As they return to headquarters together, the two make it clear that they disagree on many points regarding the future of the Shinsengumi, and see each other as rivals.

Itou: Hijikata-kun, I have a question to ask you. You hate me, don't you? Because I'm Kondou-san's favorite, and although I'm a newcomer, I'm rising to fame so fast that it threatens you. I bet I'm an eyesore to you, right?

The next day, Kondou approaches Hijikata about what happened at the swordsmith's. Because Hijikata is responsible for writing the Kyokuchou Hatto (the disciplinary framework by which the Shinsengumi live by), Kondou believes that the men see him as the ideal samurai and model themselves after him, so he shouldn't betray the rules he has laid out. However, Hijikata remains suspicious of Itou's actions and thinks that he is simply using his shameful behavior against him in order to rise up the ladder. Moreso than himself however, he's concerned about what's happening within the Shinsengumi since Itou's arrival. Hijikata is worried that Kondou wants Itou to share his position as chief. He advises strongly against this, but Kondou remains firm in his belief that he sees everyone on equal footing, and refuses to treat Itou as someone under him.

"To Love-Ru is super interesting."

Much to his dismay, the meeting with Kondou is cut short when Hijikata runs off to catch an anime program on TV. The sword seems to be taking further control of his body, as he finds himself acting like an anime otaku and continually to breaking the rules of the Kyokuchou Hatto. He starts reading JUMP in the back room, his phone rings the Pretty Cure theme song during a meeting, and he has a sleepover with a man he's supposed to be interrogating. Hijikata even finds himself on national television, arguing with Shinpachi over the practicality of being a 2D otaku vs a 3D otaku. When things have finally reached such a level of absurdity, he can do nothing more than swallow his pride and visit the Yorozuya for help.

During his visit there, the Yorozuya find out that Hijikata has been placed under suspicion indefinitely-- Itou had wanted him to commit seppuku, but Kondou and the others convinced him otherwise. However, the sword seems to have taken control of Hijikata to the point where his dismissal from work doesn't seem to phase him anymore. Shinpachi points out that Hijikata's talking as if he were a NEET (Not in Employment, Education or Training).

Hijikata:I used up most of my savings on a figurine. I guess I'll have to sell my sword.
Shinpachi: He's really pathetic! He's trying to sell his samurai soul to get a figurine!

After speaking with Murata Tetsuko, they also discover that the sword Hijikata is currently carrying is the Muramasha, a sword that harbos the spirit of a hikikomori slain by his mother. According to the legend, the boy never went to school and always watched anime. His mother snapped and killed him with the sword, so those who carry the Muramasha become posessed by the grudge of the hikikomori son. Their interest in anime increases while their interest in work and fighting decreases, and they eventually become a hopeless otaku. Though Gintoki is initially frustrated and resistant to help Hijikata any further, Shinpachi convinces him that for someone like Hijikata to put aside his self-respect and ask them for help, it must be an incredibly dangerous situation. Furthermore, they are alarmed when they find out that Yamazaki has been "killed", and Kondou is on a train with members of the Shinsengumi, and Itou has plans to assassinate him.

Hijikata: Listen up. This is my first and last request for you. Please... the Shinsengumi... My... Our Shinsengumi... protect it. Please.

"You are the soul of the Shinsengumi. We are the sword that protects you."

The Yorozuya rush to the scene in order to bring "Tosshi" to Kondou, in hopes that the urgency of the situation will awaken Hijikata again. However, nothing seems to be coming across to him, so Gintoki quickly makes an announcement as Hijikata over the system to gather the rest of the forces. He then turns in frustration to the hikikomori in the back of the car, and finally awakens Hijikata (at least, long enough for Hijikata to attack Gintoki for lecturing him):

Gintoki: Hey, are you listening? Don't retreat and shove your problems onto other people! Are you the type that asks things of others? Are you the type that shoves the fate of your Shinsengumi onto someone else? If you're going to die, die while swinging your sword alongside the things that are important to you! That's who you are!

When Kondou finally sees Hijikata approaching in the distance, he begins to feel guilty for not listening to him beforehand and letting the situation escalate. Hijikata replies to Kondou's apology with speech riddled in anime spoofs, and promises to protect Kondou's life. With his body finally back in its normal state, Hijikata approaches Itou. However, because Itou had been conspiring with the Kiheitai, they in turn have conspired against him and used the situation to destroy the Shinsengumi altogether. The train that the men are on explodes on a bridge, and Itou is left dangling for his life with only one arm left. Much to his surprise, Kondou holds out an outstretched hand to pull him up to safety, and Itou finally realizes that what he was looking for was not acceptance, but friendship.

Itou takes a number of bullets fired by the Kiheitai for the Shinsengumi and Yorozuya members, while Gintoki wards off Bansai's attacks. Eventually the Shinsengumi are able to fight off the attacks of their enemies and apprehend Itou. Though Shinpachi refuses to let the Shinsengumi kill off Itou for his crimes, Kondou insists that it is the right thing to do. Itou is granted one last battle with Hijikata, and Hijikata finally eliminates him, exposing the bond that he shares with the Shinsengumi regardless of the mistakes he had made. Itou's final words are nothing but an expression of thanks. For Itou to die alone would be the death of a filthy traitor--Gintoki explains to Shinpachi that the reason the Shinsengumi decided to kill him themselves, was that so he could die the death a samurai and fellow comrade deserved.

After the battles are over, the Shinsengumi are unsure that they'll be able to return back to the way they were after everything that had happened. However, Hijikata storms into the building, listing off rules from the Kyokuchou Hatto and threatening seppuku as if nothing had ever happened. The men run up to him, covered in tears and snot and embrace the angry and violent vice commander they all know and love. That is of course, until his cell phone rings the Pretty Cure theme song once again.

Kondou: Toshi... you said I was the soul of the Shinsengumi. But to these guys, you're also an irreplacable part of that soul. Good to have you back, Toshi.