Despite being a female teacher, Lisa, who descends from a lineage of shrine maidens, secretly fights as an exorcist warrior eliminating Mōmajū—demonic entities that possess humans and cause harm. One day, a series of malicious incidents occur at her school, leading her to discover the presence of a mysterious evil spirit. Guided by information from her partner, a kappa yōkai, she learns that an incubus-type Mōmajū, feeding on human lust, is lurking within the academy. To identify which students have been possessed, Lisa begins fulfilling their lewd requests. However, her methods are seen as excessive and inappropriate, drawing fierce criticism from parents. Suspected students become her targets as she resorts to intimate acts as a means of exorcism. But the true identity of the incubus turns out to be an unexpected victim—the school's bullied outcast. When Lisa's illicit encounters with students are exposed, she faces relentless condemnation from the parents, ultimately leading to a tragic downfall.