Muraki's fianceé and Oriya's friend, who works for Sakura Pharmaceuticals. She has the appearance of a high-school girl, despite being in her thirties. She is two years younger than Muraki and Oriya, and went to school with them. After Muraki's disappearance following the events in Kyoto, Ukyou began visiting Oriya every year in his place. She seems to be a relatively good person with rather poor health.
It is unknown is she knew her fiancé raped a young boy and killed people and it's unclear if she knows Muraki was being unfaithful to her for lusting after Tzusuki.