Who Is the Traitor in Jujutsu Kaisen?

The Kyoto Goodwill Event Arc of the Jujutsu Kaisen manga and anime was one of the more interesting ones, as it expanded the initial world of Jujutsu Kaisen and introduced us to a series of new characters and elements from the lore. But, while the event itself was everything you’d want from a good anime arc, it also revealed that there was a traitor among the Jujutsu sorcerers, someone who was leaking information to the enemy (namely Mahito and Kenjaku, who was then known as Pseudo-Getō). And while the arc itself, especially the anime, never confirmed the identity of the traitor, we have done our research and in this article, you are going to find out the identity of the traitor in Jujutsu Kaisen.

Chapter 79 of the Jujutsu Kaisen manga confirmed that the traitor was none other than Kyōto’s own Kōkichi Muta, also known as Mechamaru. Due to his specific condition, Mechamaru had to stay hidden in the shadows, as in any other case, he would have died. In order to gain a healthy and functional body, Mechamaru made a Binding Vow with the enemy: he would leak information to them in exchange for a healthy body, but they couldn’t hurt his fellow Kyōto classmates. After gaining a healthy body, he tried to kill Mahito and Pseudo-Getō but ultimately died himself.

The rest of this article is going to elaborate further on the answer we have given you and will tell you more about Mecamaru and his role in the story of Jujutsu Kaisen. Now, the identity of the traitor was a very important fact in the series, and it had many plot-related implications, which is why we are going to tell you everything you need to know about it. The article is going to contain many important spoilers, so we just wanted to warn you beforehand.

The traitor was…

You know the answer from above, so it’s no major surprise, but we’ll just give you some context. In Chapter 33 and Episode 14 of Jujutsu Kaisen, Utahime Iori of the Kyōto Metropolitan Curse Technical College meets with Gojō, who informs her that he is aware of a spy in their ranks and that he wants her to investigate her school to see whether the spy is coming from Kyōto.

Utahime asks him why he trusts her, as she could very well be the spy, but Gojō simply replies that she couldn’t do it, to which she throws a teacup at him. And Gojō was right, as Utahime really wasn’t the spy, but they were right about the spy coming from Kyōto.

Sadly, the arc never really provided us with an answer to this question. The event was finished, and the Kyōto Metropolitan Curse, Technical College members, simply returned to their hometown without us ever finding out who the traitor, i.e., the spy was. Utahime did have a moment where she supposedly revealed their identity to some characters, but this was interrupted by Kasumi Miwa calling out Mechamaru’s name.

And while the panel was highly suggestive, it wasn’t actually a full and proper confirmation that Mechamaru was the traitor, as it could have easily been a red herring. Now, the traitor was revealed later in Chapter 79, when it was revealed that the hint was not a red herring and that the traitor was, indeed, Mechamaru.

In Chapter 79, Mahito and Pseudo-Getō arrive at a secret location, where Mechamaru greets them, stating that he thought they had betrayed him. After a brief discussion, the two agree to use Mahito’s Idle Transfiguration technique to heal Mechamaru’s original body in exchange for the information he has provided them with.

Namely, Kōkichi Muta, also known as Mechamaru, was born with an illness that prevented him from facing any light, which is why he used cursed bodies to be in the outside world while he himself was hiding in a dark hideout, far away from everyone. What he desperately wanted was a functional body. Knowing that Mahito could provide him with one, he made a Binding Vow with the villains: he would provide them information on the Jujutsu sorcerers, and they would provide him with a healthy body; another condition was that the villains would not harm his fellow Kyōto Metropolitan Curse Technical College classmates.

The villains finally agreed, and thanks to Mahito’s technique, Kōkichi Muta was finally given a fully functional, healthy body.

And while this confirmed that Mechamaru was the traitor in Jujutsu Kaisen, it also implied that he was now with the villains, but this did not happen, as Mechamaru was the series’s villain. Once he got his body, he activated his Mechamaru Mode: Absolute, and the two of them immediately engaged the two villains in the hideout, thus proving Mechamaru’s true intent.

As you can see, he was never a villain nor really joined the villains. Sure, he became a traitor, but this was due to personal reasons. And while he was an ass towards the guys from Tokyo, he still cared enough for his Kyōto Metropolitan Curse Technical College classmates, so he ensured they were safe.

He wanted a body, he simply wanted to be normal, and he wanted to finally meet his classmates in person, which is why he made the Binding Vow with the villains. It wasn’t the best option. It was also not the worst.

And while he was ready to become a traitor to become normal, his actions in the future demonstrated that he was never a villain. Namely, as soon as he got his body, he revealed his intention to kill his two guests, the villains, and engaged Mahito with his robotic cursed body.

The fight was truly intense, but Mahito barely managed to defeat his two opponents and kill them both. Mechamaru thus failed in his attempt, and there was some poetic justice in that, but despite getting his body, he never did see his friends and classmates, which makes his story one of the sadder ones in the series.