Description
Sayaka Kamoshida, the oldest member and a graduate student in Kikka University's Occult Research Club, harbors intense romantic feelings for lecturer Shuichiro Takanashi. This longing drives her to take extreme actions for his approval and affection. Her primary motivation leads her to orchestrate the theft of the mystical Stone of Life from a coffin in the university's data warehouse during a club expedition. The artifact was embedded within Euphrosyne Studion, a noblewoman reanimated as a zombie through dark magic. Sayaka steals the stone to aid Shuichiro's research into immortality and reanimation, unaware of his manipulative intentions and incestuous relationship with his sister, Mako. Her theft directly triggers the resurrection of Euphrosyne and her homunculus maid Alma V after a century of slumber; both pursue the club members to reclaim the stone.

Throughout the ensuing chaos, Sayaka's decisions prioritize pleasing Shuichiro, often endangering her fellow club members. She passes the stolen stone to him, enabling his experiments, including embedding it into Mako's body to grant her immortality. As Euphrosyne and Alma close in, Shuichiro uses Sayaka as a hostage in a confrontation. Mako, viewing the hostage situation as a hindrance, kills Sayaka by throwing a shard of glass that pierces her head. This eliminates Sayaka before she witnesses the full consequences of her actions or achieves resolution regarding her feelings.

Sayaka's background beyond her club role and connection to Shuichiro is not elaborated. Her character arc is defined by single-minded devotion that blinds her to moral compromises and dangers, resulting in her instrumental role in unleashing supernatural forces and her own demise. Other club members, like Masahiro Abe, perceive her as self-centered and driven by misguided loyalty. Her story concludes within these events, with no further development or appearances in sequel media. The stone's origins and full capabilities remain unexplained beyond its role in sustaining Euphrosyne's existence and granting immortality.