Sanji Yaguchi

Stripe-like markings run across much of Sanji's body, and he is usually dressed down in a hooded top. His hair is kept short and brown, matching a pair of brown eyes.

As a Post-human, Sanji operates well beyond ordinary human limits, and a prosthetic arm converts his boxing background into a lethal instrument. Investigators conclude that this mechanical limb is what allowed him to kill a grown man with one blow, tearing the head clean off. His former life inside the ring only sharpens how efficiently he delivers that kind of force.

Section 9 first logs Sanji as one of only three confirmed Post-humans operating inside Japan, alongside Suzuka Mizukane and Takashi Shimamura. He announces himself when a journalist films him killing Koichi Tadakoro out in the open street, and the unit begins piecing together his motive. Digging into his past, Batou and Togusa learn from his old boxing coach that Sanji had chased a title in hopes of becoming a public face for the Tokyo Rising effort, and that a strange fever struck him during training, which the coach pinned on augmented-reality sparring.

Purin surfaces earlier deaths matching his method. The trail runs back through Ishiwata, thought to be his first victim, a man who had funneled refugees into citizenship and Tokyo Rising jobs, many of whom drew benefits without ever working. Koichi, it emerges, had signed off on those same citizenship approvals. With every victim tied to the project's contracts, the Chief and the Major warn Prime Minister Chris Otomo Tate that his father-in-law Sachio Otomo could be next, and that the man's role may have brushed against the project's dirtier dealings. Sanji kills Sachio all the same.

To bait the killer out, Tate publicly claims the chairmanship for himself. Sanji takes the lure and confronts the procession carrying Sachio's coffin, demanding to know Tate's true purpose; Tate answers that his devotion to rebuilding the nation is genuine. Before Sanji can respond, the Major springs a trap she has prepared by studying his fighting style, beats him down, and clamps a cyberlock onto him so he can be hauled away. His surname is written with characters carrying the senses of arrow and mouth or entrance.