TV-Series
Description
Hanyū, an ancient deity originally named Hai-Ryūn Ieasomūru Jeda, migrated with her clan to the region that would become Hinamizawa, seeking coexistence with humans. Discrimination against her horned appearance led to conflict. After marrying human Furude Riku and bearing a daughter, Ōka, she attempted to mediate peace. Instead, Ōka sacrificed her during the first Watanagashi Festival using the sacred sword Onigari-no-ryuuou. This sacrifice cracked one of her horns and transformed her into the revered Oyashiro-sama, confining her to an incorporeal form for centuries.

For over a thousand years, Hanyū observed Hinamizawa's inhabitants, unable to interact physically. This changed with the birth of Furude Rika, the eighth-generation heir of the Furude family, who could perceive and communicate with her. Hanyū acted as a maternal figure, teaching Rika essential skills. When Rika began experiencing repeated deaths in June 1983, Hanyū used her powers to traverse the Sea of Fragments, enabling Rika to loop through timelines to evade fate. However, Hanyū's abilities weakened over time, eventually restricting loops to only two weeks before Rika's death. The cracked horn also caused Rika's incomplete memories of past fragments.

Hanyū typically manifested as a timid, anxious entity, using verbal tics like "Au au" and "nano desu," and often apologizing to those afflicted by Hinamizawa Syndrome—a condition linked to her hybrid lineage. Her presence explained auditory phenomena like footsteps heard by Syndrome sufferers. She could temporarily assume physical form, such as when posing as a transfer student, and wielded abilities including time manipulation, teleportation, and mind control. Her senses remained intrinsically linked to Rika's, creating shared experiences of pain or taste.

In Higurashi Gou, Hanyū's powers diminished further after Rika achieved a peaceful timeline and left Hinamizawa. When Rika returned to the loops due to Satoko's interference, Hanyū could only offer fragmented guidance. She revealed the location of the Onigari-no-ryuuou—interpreting its power as a means for permanent termination of loopers—before disappearing entirely, leaving Rika to navigate the new cycles alone.

Expanded lore in Gou and Sotsu introduced Eua, a higher-dimensional entity who identified Hanyū as a "fragment" created when Eua's horn was damaged. This retroactively positioned Hanyū as an offshoot of Eua's consciousness. In later conflicts, Hanyū briefly manifested to empower Rika with residual fragment energy during a confrontation with Eua, enabling Rika to damage Eua's horn.

Hanyū's relationship with Rika evolved from guardian-like care to mutual dependence across centuries of loops. Despite Rika's occasional harsh treatment, Hanyū expressed willingness to endure endless repetitions solely to remain with her. This bond contrasted with her distant role as Oyashiro-sama, a persona she disliked due to its association with forced sacrifices.