Yuu Saiga works at a local deli. Her undeveloped psychic abilities grant her insight into paranormal phenomena, especially those affecting Eiri Kurahashi. These powers let her sense the supernatural roots of Eiri's deepening obsession, though she lacks full comprehension of the specific events or entities responsible. Within Eiri's social circle, Yuu is among the women who notice the troubling shifts in his behavior and mental state. Her psychic sensitivity makes her an observant witness to the haunting influence surrounding Eiri, yet her character is defined primarily by this supportive role. Across all official media, Yuu Saiga's background and narrative function remain consistent, with no significant expansion beyond these established traits.