Fusshi is a yokai from the anime The Morose Mononokean II. Introduced early in the series, this creature is responsible for the persistent weakness and lethargy experienced by the human protagonist, Hanae Ashiya, prior to the main events of the story. Fusshi has the ability to attach itself to a human host and drain their energy, which manifests in the human as seemingly unexplained anemia or chronic fatigue.

In terms of personality, Fusshi does not act out of malice but rather instinct. Its energy-draining behavior, while harmful to the host, is an innate need for the yokai. Over the course of the narrative, Fusshi’s relationship with Hanae evolves significantly from a parasitic, harmful connection to a more cooperative and improved bond. This change is central to Fusshi’s role in the story, moving from being the cause of Hanae’s initial ailment to an example of the complex but manageable interactions between humans and yokai that The Morose Mononokean II explores.

Fusshi’s motivations are simple and tied to its nature as a yokai, primarily focused on its need to feed on human vitality to sustain itself. Its notable ability is this very energy absorption, a power that can be debilitating for the human involved. The character’s development is shown indirectly through Hanae’s journey, as the resolution of their early conflict sets the stage for Hanae’s deeper involvement with the spirit world. By the second season, the initial incident with Fusshi is referenced as a key event that led Hanae to the Mononokean and his subsequent understanding of yokai, including learning to manage creatures with similar nature to Fusshi.