In a world where the supernatural and the mundane intertwine, Kou Minamoto's life takes an unexpected turn when he becomes the reluctant assistant to Hanako-san of the Toilet, one of the Seven Mysteries of Kamome Academy. Once determined to exorcise this ghostly entity, Kou now finds himself thrust into a realm of shimmering boundaries and ethereal spirits, guided by the mischievous yet enigmatic Hanako
As Kou navigates the delicate balance between the mortal and spirit worlds, he discovers that not all supernatural beings are malevolent forces to be banished. Through encounters with lost souls, ancient mysteries, and the complex politics of the spirit realm, Kou's black-and-white view of exorcism is challenged, forcing him to question everything he thought he knew.
Amidst this supernatural education, Kou grapples with his growing feelings for Hanako, whose playful demeanor masks a deep sadness and dark secrets. Their partnership is further complicated by the arrival of Tsukasa, Hanako's twin brother, whose behavior towards Kou very odd.
With the support of his friend Nene Yashiro and the watchful eye of his exorcist brother Teru, Kou must learn to balance his duties as a student, an exorcist-in-training, and Hanako's assistant. As he uncovers more about the Seven Mysteries and the forces that threaten to upset the supernatural balance, Kou realizes that his role in this hidden world may be far more significant than he ever imagined.