Miyū Aikawa is a sixteen-year-old first-year student at Seimei High School who works as a popular online fortune teller. She broadcasts her live fortune-telling sessions on NicoNico Video under the handle Myu and has attracted a dedicated fan club at her school. She is consistently cheerful, hyper, and smiling, projecting a friendly, moe-inspired persona that contributes to her online popularity.

Behind this bright exterior, Miyū possesses genuine clairvoyant abilities. Several days before the murder of Professor Isayuki Hashigami, she entered a trance state and contacted his son, Sarai Hashigami, urgently advising him to visit his father. Her warning turned out to be accurate, marking her as one of the individuals drawn into the unfolding conspiracy. She later becomes a collaborator with Yuuta Gamon, joining him in working on his occult-aggregation blog Kirikiri Basara, and develops a close friendship with him, addressing him as Gamo-senpai. She also becomes friends with reporter Touko Sumikaze after being interviewed for the occult magazine Mumuu.

Her role in the story is that of a gifted psychic whose abilities are both a tool and a liability. She is listed among the 256 victims of the 256 Incident, a mass drowning orchestrated by the Musashino Medical Group, revealing that she is a target of the organization’s experiments. Throughout the narrative, her seemingly trivial discomforts and predictions foreshadow larger events, and her clairvoyance proves critical in uncovering the truth behind the conspiracy. Her character develops from a carefree online personality into someone who must confront the serious, life-threatening nature of the supernatural forces at work around her. Her notable ability is her fortune telling, which manifests as spontaneous trance-induced visions that provide accurate, if cryptic, insights about future events and the fates of those connected to her.