Hanae Ashiya, a high school student, becomes entangled in the supernatural after encountering a mysterious, sickly yokai (spirit) in his school. Unable to shake off the yokai, which clings to him and drains his energy, Ashiya seeks help from the Mononokean, a tea room run by Abeno Haruitsuki, a young exorcist who specializes in guiding yokai to the underworld. Ashiya reluctantly agrees to work for Abeno to pay off the exorbitant fee for his services, setting the stage for their partnership.

The narrative revolves around Ashiya and Abeno’s efforts to assist various yokai in resolving their earthly troubles so they can pass on to the underworld. Each episode typically introduces a new yokai with unique problems, ranging from unresolved emotions to physical entrapments in the human world. Ashiya, initially inexperienced and fearful, gradually develops a deeper understanding of yokai and their struggles, often approaching them with empathy and compassion. Abeno, on the other hand, maintains a more pragmatic and detached demeanor, though his past and motivations are slowly revealed as the series progresses.

The dynamic between Ashiya and Abeno forms the core of the story. Ashiya’s cheerful and empathetic nature contrasts with Abeno’s reserved and sometimes aloof personality, creating a balance that drives their interactions and growth. Over time, their partnership evolves from a transactional arrangement to a genuine camaraderie, with both characters learning from each other’s perspectives on life, death, and the supernatural.

The series also delves into the backstory of Abeno, particularly his connection to the Mononokean and his role as an exorcist. Flashbacks reveal his childhood and the circumstances that led him to inherit the Mononokean, shedding light on his guarded personality and the weight of his responsibilities. Ashiya’s presence begins to challenge Abeno’s solitary approach, prompting him to confront his own emotions and past.

Throughout the series, the Mononokean itself serves as a central element, acting as both a gateway to the underworld and a space where yokai and humans can interact. The tea room’s enigmatic nature and its ties to the supernatural world add depth to the narrative, emphasizing themes of coexistence and the transient nature of life.

The story maintains a balance between episodic yokai-focused arcs and overarching character development, blending moments of humor, melancholy, and introspection. The yokai themselves are portrayed with nuance, often reflecting human emotions and struggles, which adds emotional weight to their stories. The series explores themes of closure, empathy, and the interconnectedness of the human and supernatural realms, offering a thoughtful and engaging exploration of its premise.