Furude Hanyū, whose true name is Hai-Ryūn Ieasomūru Jeda, is a central figure originating over a millennium ago as a demon goddess. She arrived with her clan at Onigafuchi Swamp, later called Hinamizawa. Seeking coexistence with human villagers, she faced discrimination due to her horns. She married Furude Riku, the Furude Shrine heir, who gave her the nickname "Hanyū" based on his interpretation of her clan's name. Their daughter, Furude Ōka, began a lineage blending demon and human blood, which later contributed to Hinamizawa Syndrome. To protect villagers from perceived demonic threats, Hanyū orchestrated her own sacrifice. She allowed herself to be framed as a demon corrupting humans, leading to the first Watanagashi ceremony. At her request, Ōka killed her using the sacred sword Onigari-no-ryuuou. This act cracked one of Hanyū's horns and transformed her into the revered guardian deity Oyashiro-sama. Posthumously, she existed in an incorporeal form, invisible to humans but bound to Hinamizawa. Her lingering presence caused auditory hallucinations (footsteps, apologies) in individuals with advanced Hinamizawa Syndrome, exacerbating their paranoia. Centuries later, Hanyū formed a profound bond with her descendant Furude Rika, the first human able to perceive her since Ōka. She acted as a maternal figure, teaching Rika skills like cooking. Their senses became linked, allowing Hanyū to experience Rika's physical sensations. Following Rika's repeated deaths each June 1983, Hanyū used her diminishing powers to transport them both to new temporal fragments, resetting events two weeks prior to each tragedy. This looping persisted for approximately a century. Hanyū initially discouraged Rika's hopes to shield her from despair while secretly valuing their extended time together. Hanyū is characterized by timidity and politeness, frequently uttering "au au" when distressed or excited. She typically uses the masculine pronoun "boku" and ends sentences with "nano desu." Despite her gentle demeanor, she exhibits a stern, goddess-like persona ("Adult Voice") when angered or invoking divine authority, often accompanied by glowing red or purple eyes. She harbors deep guilt over her past actions and the suffering caused by her unseen apologies. In the fragment culminating in Matsuribayashi-hen, Hanyū manifested physically as a transfer student posing as Rika's distant relative. Her horns went largely unremarked except by Takano, who called her a "monster." She collaborated with Rika's friends to thwart Takano's plans, employing psychological warfare by impersonating Oyashiro-sama to intimidate adversaries. Her abilities included time manipulation, teleportation, flight, mind control, and briefly wielding the Onigari-no-ryuuou against her counterpart Eua in Kagurashi-hen. She also demonstrated power-dampening effects on individuals enhanced by other entities. Hanyū's relationship with Rika evolved across fragments. She often endured Rika's frustrations due to their linked senses, such as Rika consuming spicy food or alcohol to discomfort her, but remained fiercely devoted. In later arcs, Hanyū drew courage from Keiichi Maebara's example, inspiring Rika to confront fate. Her connection to Rena Ryūgū was notable; Rena sensed Hanyū's presence during spiritual encounters, and Hanyū inadvertently prevented Rena's suicide attempt during her parents' divorce. In *Higurashi Gou* and *Sotsu*, Hanyū's origins were clarified. She is a fragment of Eua, created when Eua's horn was damaged. Eua dismisses Hanyū as a "failure" and her "incomplete" self. The crack in Hanyū's horn from Ōka's strike weakened her powers, causing Rika's incomplete memory retention during loops. Ultimately, Hanyū empowered herself using fragments of reality to defeat Eua.