Tsumiki Fushiguro in Jujutsu Kaisen is Megumi Fushiguro’s gentle, non- sorcerer older stepsister whose fate becomes one of the core emotional drivers of his character arc.

Who Tsumiki Is

  • Tsumiki is Megumi’s older stepsister , and the step‑daughter of Toji Fushiguro.
  • She’s an ordinary human with no innate cursed technique or combat role; her main importance is emotional, grounding Megumi and motivating many of his choices across the series.
  • In flashbacks, she’s shown as kind, responsible, and protective toward Megumi, acting as his main source of warmth in a pretty rough childhood.

Her Curse and Coma

  • During one of Kenjaku’s large‑scale Idle Transfiguration schemes, Tsumiki is cursed and falls into a long coma that lasts around a year and seven months.
  • This event quietly sets up the Culling Game plot, because her condition becomes the big reason Megumi wants to cooperate and get stronger: he’s trying to save Tsumiki more than himself.

Role in the Culling Game

  • When the Culling Game begins, it’s revealed that Tsumiki was unknowingly selected as a player and transformed into a suitable vessel through Kenjaku’s modifications.
  • After waking, she enters a colony, rapidly gains points, and uses them to add a new rule that allows movement between colonies, which at first looks like clever survival, but actually hints that something is “off” about her personality.

The Yorozu Reveal

  • The twist is that “Tsumiki” in the Culling Game is not truly herself: an ancient Heian‑era sorcerer named Yorozu has reincarnated into her body.
  • Using Tsumiki’s memories, Yorozu manages to deceive Megumi until she reveals her real identity, laughing and acting in a way completely unlike the quiet, kind girl he remembers.
  • Yorozu becomes obsessed with fighting Sukuna, seeing him as a long‑awaited opponent, and uses Tsumiki’s body as the stage for that battle.

Her Fate (Major Manga Spoilers)

  • Once Yorozu is fully incarnated in Tsumiki’s body, her own consciousness is effectively erased; she’s no longer in control.
  • Sukuna, now using Megumi’s body, ultimately kills Yorozu, which simultaneously ends Tsumiki’s life as the vessel.
  • Later, Shoko Ieiri prepares Tsumiki’s corpse for cremation with Megumi’s consent, closing out one of the most tragic threads in the series.

Why She Matters in JJK

  • Even with limited screen time, Tsumiki functions as the emotional cornerstone for Megumi: she’s the “normal life” and family he wants to protect, so her loss hits especially hard.
  • Fans often debate whether she’s underdeveloped or used mainly as a plot device, but many discussions point out that her off‑screen influence on Megumi’s choices is huge and deliberate.
  • In current fandom talk and forum threads, “who is Tsumiki in JJK” usually means both “Megumi’s sister” and “the vessel for Yorozu whose tragedy helps push the Culling Game and Sukuna arcs into their darkest territory.”

TL;DR: Tsumiki in JJK is Megumi’s kind, non‑sorcerer stepsister who’s cursed, turned into a Culling Game player, and revealed to be the vessel for the ancient sorcerer Yorozu, leading to one of the series’ most tragic plotlines.

Information gathered from public forums or data available on the internet and portrayed here.