Warning: Spoilers concerning Yuji’s and Choso’s respective parentage ahead
The latest episode of Jujutsu Kaisen’s second season, episode 13, showcased one of the most impressive fight sequences in the anime’s history so far, only to end with a resolution most fans weren’t prepared for. Not in a bad way, more of a “what-in-the-world-is-going-on?” kind of way. If you haven’t read Gege Akutami’s manga, at least the entirety of the Shibuya Arc, you were most likely left feeling puzzled by the reason as to why Choso didn’t kill Yuji Itadori, and even more so by the odd fake flashback that enters the human-curse hybrid’s mind.
The fake memories aren’t the result of anything Sukuna has done, as some anime-only fans thought when first watching. In truth, these are triggered by something Choso has been shown to be capable of passively doing since he was introduced in the last episode of season 1. An inherent ability that spells out a connection he could not have foreseen he had in common with the same jujutsu sorcerer who killed his two younger brothers.
Blood of my blood
In season 1, episode 24, viewers are introduced to Choso as he realizes, during a board game with Mahito and not-Geto, that Kechizu and Eso were killed. A similar sensation, accompanied by the startling “memories that didn’t exist”, is what causes Choso to essentially freak out and fail to deal the finishing blow to a dying Yuji in season 2, episode 13.
The pattern Choso sees forming on the pool of blood on the floor symbolizes the blood bond that connects him to the one he had perceived as a mortal enemy up until this point. At this stage in the story, we don’t know who Yuji’s parents are but we come to find out that his lineage, particularly on his mother’s side, is quite tricky.
Essentially: Yuji and Choso are half-brothers. And the common link is pseudo-Geto, or rather, the ancient sorcerer Kenjaku. Before overtaking Suguru Geto’s corpse, Kenjaku had been quite the busy, naughty man. Prior to planting his brain into the curse manipulation user’s body, and for an unknown period of time, Kenjaku posed as Kaori Itadori and, for his own nefarious reasons, had Yuji with her partner Jin Itadori.
Following so far? Great, because the mind-boggling family history does not end here. Over a hundred years before Kenjaku used his innate technique to take over Kaori’s body, he had transplanted himself into Noritoshi Kamo – the ancestor, not the Kyoto High student who’s named after him. During that time, he would forever stain Noritoshi’s reputation as one of the evilest sorcerers to have ever lived, greatly thanks to the disturbing research he conducted on the Cursed Womb: Death Paintings.
The Death Paintings, one of which incarnated as Choso, are a total of nine special-grade objects born as half-curses from a human mother. Noritoshi, possessed by Kenjaku, mixed a portion of his blood with some of the Death Paintings. Even though they existed as cursed objects for over 150 years, Choso, Kechizu, and Eso only acquired their humanoid physique – human-like to visibly differing degrees – around the time of the Goodwill Event between Kyoto and Tokyo Jujutsu High.
So, even if it’s far from conventional to say the least, Kenjaku is technically Choso’s father. He can also be considered to be Yuji’s – or his mother, depending on how you decide to perceive this bizarre familial relation. Hence, the one Choso had as a target to kill on sight until the end of episode 13, is in actuality, another little brother he feels compelled to protect.