TV-Series
Description
Izumi is the mother of Mizuha, a descendant of the immortal being Fushi's long-time observer, Hayase. She is a member of the Guardian cult, a lineage that has historically been intertwined with the Nokkers. Her background is marked by significant personal trauma, having been raised by an abusive father who forced her into becoming a successor within the Hayase legacy and pressured her into an arranged marriage to produce a stronger next generation for the cult. Desperate to escape this fate, Izumi ran away and married a man she chose herself, hoping to build a truly happy life and protect her future daughter from the cult's influence.

On the surface, Izumi appears to be a controlling and overbearing parent, constantly pushing Mizuha to excel in various disciplines without regard for her daughter's feelings. This behavior leads to a strained and distant relationship, with Mizuha feeling that her mother treats her as a trophy. However, this conduct stems from a deep-seated fear; Izumi's extreme pressure was her misguided attempt to prevent Mizuha from being drawn into the Guardian cult and becoming the 18th successor. Her motivations are rooted in love and a desire for her daughter to have the freedom she was denied, but her methods tragically push Mizuha away.

Izumi's role in the story is central to Mizuha's arc and the exploration of the Nokkers' influence. After learning that her chosen husband was secretly a member of the cult who had been deceiving her all along, Izumi was overcome with despair and wished for death, which allowed a Nokker to enter and possess her body. This possession caused her to lose memories and faint periodically, leading to her eventual death and subsequent revival by the Nokker, which began puppeting her form. Her development comes after death, as her spirit remains to witness events. A key moment occurs when Mizuha, under the Nokker's influence, declares that the false, Nokker-controlled version of Izumi is a better mother than the real one ever was. Hearing this, the ghost of the real Izumi can only cry, fully confronting the unintended consequences of her oppressive parenting.

Izumi's most significant relationship is with her daughter, Mizuha. Her life is a cycle of abuse, as her own father's mistreatment caused her to become an unwilling source of suffering for her child. Her relationship with the Nokkers is also critical; they are the entities that exploited her vulnerability and eventually took control of her life and body. Izumi possesses no notable supernatural or combat abilities, but her deep connection to the Guardian cult's legacy makes her a vessel for the Nokkers. A notable quirk is her obsessive habit of taking selfies, which is implied to be a result of her losing her sense of identity and needing to confirm her own existence as she began to lose control of her body and mind.