Hanyu, revered as Oyashiro-sama, is a millennia-old entity who journeyed with her clan to Onigafuchi Swamp (later Hinamizawa) seeking human coexistence. Facing discrimination over her horned appearance, conflict arose. She married Furude Riku, heir to the shrine, who affectionately nicknamed her Hanyu after mishearing her true name, Hai-Ryūn Ieasomūru Jeda. Their daughter Ouka, the first human with demon blood, originated Hinamizawa Syndrome through mixed lineage. To quell rising village paranoia, Hanyu embraced demonization and was sacrificed by Ouka using the Onigari-no-ryuuou sword, cracking her horn. This event established the first Watanagashi festival, with villagers later worshipping her as Oyashiro-sama, unaware they had killed their deity. Following her death, Hanyu existed incorporeally for centuries, unable to interact physically until the birth of Furude Rika. As Rika's ancestor and guardian, she became a mother figure, imparting domestic skills. Their senses linked, sharing pain and taste. Each time Rika died in June 1983, Hanyu triggered time loops ("Fragment jumps"), resetting events roughly two weeks prior. However, her powers waned over cycles, restricting memory retention and shortening loop duration. Her cracked horn contributed to Rika's fragmented recollection of past events. Physically resembling an 11-year-old, Hanyu possesses purple eyes, light purple hair, and dark purple horns—the left one cracked. She typically wears shrine maiden attire or school uniforms. In her goddess form, her eyes glow red or purple. Her timid personality features verbal tics like "au au" when distressed and the self-referential male pronoun "boku." She often exhibits pessimism about altering fate and apologizes to those suffering Hinamizawa Syndrome; her unseen presence caused the "mysterious footsteps" in the series. When angered or using powers, her voice shifts to stern maturity. Her abilities encompass time manipulation, flight, teleportation, time-freezing, and mind control. She could temporarily suppress Hinamizawa Syndrome. Later arcs revealed combat prowess wielding the Onigari-no-ryuuou sword. Her connection to Eua (Gou/Sotsu) exposed Hanyu's origin as a fragment of Eua created after her horn was damaged. Hanyu's relationship with Rika evolved across loops. Initially overprotective, she encouraged resignation to spare Rika disappointment. Witnessing Rika's determination and Keiichi's defiance shifted her perspective. In Matsuribayashi-hen, she materialized visibly as a transfer student, directly aiding the club's plan against Takano. This culminated in confronting Takano at the shrine, offering divine forgiveness before being shot. Her arc concluded as she sacrificed her residual powers to ensure Rika's permanent escape from looping. Philosophically, Hanyu embodied observational passivity versus intervention. Her allowance of repeated tragedies stemmed from a belief that enduring hardship fostered growth, contrasting Frederica Bernkastel's nihilism, reflecting thematic parallels to a "damaged rose" thriving through adversity.