Hanyuu Furude

Hanyū was once known as the demon god of Onigafuchi (Hinamizawa) under her true name, Hairyūn Yeasomūru Jeda. She travelled with her clan to the Onigafuchi Swamp and tried to coexist with the human villagers there, but she was discriminated due to her horns. However, Furude Riku, the heir to the Furude shrine and inventor of the nickname "Hanyū", fell in love with Hainiryūn and married her. They had a daughter named Furude Ōka, the first in a long lines of humans to carry demon blood. To protect the villagers from demons, she had to sacrifice her husband and lost her ability to appear in front of humans. Nobody was able to see her except for her daughter. To combat a strange disease that was spreading throughout the country, she created medicine and gave it to her daughter. However, powerful men desired the medicine for their political purposes and her daughter was captured. Driven by fear for the safety of her daughter and bitterness from the betrayal of the very people she saved with the medicine, she became corrupted as a demon and massacred the villagers. Her daughter, knowing she had become corrupted with evil thoughts, battled Hanyuu and successfully stabbed her with a sword. This brought Hanyuu back to sense; however, knowing she would one day turn evil again, she begged Ooka to kill her using her own sword, the only weapon capable of killing a demon. Since Hanyuu's death, the villagers revered Ooka for driving away the "demon" and the legend of Oyashiro's curse started.[1]