Ayumi Murai attends an academy rife with occult activities. She regularly seeks tarot readings from classmate Kaori Saeki, primarily concerning her romantic feelings for fellow student Asada. When Saeki's cards suggest Asada is committed to another relationship, Murai requests black magic to alter his affections. Saeki refuses, leading Murai to accept help from Taki Minase. Minase uses a paper charm inscribed with Asada's initial in Murai's blood to cast a spell. In the anime adaptation, this spell causes Asada to immediately confess love upon encountering Murai in a hallway, leading to public intercourse halted by student council president Rika Shiraki. The game version shows a less explicit outcome, with only a confession of feelings during the hallway encounter. After this success, Murai approaches Minase again, seeking magic to enhance Asada's sexual endurance, a request he rejects. In the sequel game *The Infection*, Murai's involvement deepens under magical influence. One month after the initial events, she consults Saeki's tarot, interpreting the reading as a warning about rivals to her relationship. Later, affected by a pervasive lust spell at the school, she propositions Minase, expressing romantic interest and envy toward his relationship with Kurumi Imari. Depending on player choices, she either engages in intercourse with Minase or reports the incident to art teacher Hiroko Takashiro, who erases her memory. As supernatural corruption intensifies, Murai participates in group sexual activities, including an encounter with Minase and Saeki in the art club room and an orgy in the school basement intended to resurrect Reika Kitami. Murai readily believes in the efficacy of occult practices like tarot and magic. She displays insecurity in romantic matters, heavily relying on external validation. After securing Asada's affection, she expresses guilt over her manipulative actions while simultaneously reveling in her perceived desirability. Her sexuality is overt; she acknowledges daily sexual activity with Asada and critiques his performance. A minor inconsistency exists regarding her given name. Introduced as "Ayumi" in the first game, Minase later refers to her as "Motoko Murai" without explanation. This alternate name is absent in anime adaptations and the sequel game. Chronologically, Murai and Asada's hallway encounter represents the first explicit sexual incident depicted in the series.