The largest island in the Rougetsu Archipelago, situated in the sea south of Honshu. On the night of the lunar eclipse every ten years there was a dance held there, known as the Rougetsu Kagura, in which shrine maidens would dance to the island's native music. After the last kagura, most of the islanders were found dead, and since then no one has visited the island, treating it as taboo.
A grand sanatorium that was built for the treatment of Getsuyuu Syndrome, a disease endemic to the area around Rougetsu Island.
An old hospital that has been on the island since before Rougetsu Hall was built. The islanders refer to the newly-built Rougetsu Hall as the "new building", and Haibara Hospital as the "old building".
A girl learning to play the piano who was brought up on Rougetsu Island. 17 years old. She remembers nothing from before the incident in which she was spirited away. Each time she plays the only melody she remembers, she recalls a fragmented memory - what lies beyond that scene... the house where she was born, her father, and about herself... She wants to remember these things, and shaking off her mother's orders she makes her way to Rougetsu Island.
A strong-willed, selfish girl. 17 years old. She is one of the five who were spirited away, and a descendant of the creator of the Camera Obscura, Dr. Kunihiko Asou. "Come back... to Rougetsu Island..." Led by the words of the girl in black reflected in the mirror, she heads for Rougetsu Island with Madoka.
A timid girl who does whatever Misaki tells her to do. 17 years old. After wo of her friends who were rescued after being spirited away, Tomoe Nanamura and Marie Shinomiya, die simultaneously, she becomes worried about changes in Misaki's demeanour.
An investigator who formerly worked as a detective. During his pursuit of You Haibara, a suspected serial killer, to Rougetsu Island during his police days, he became involved in the spiriting away incident and discovered the girls. At the request of Sayaka, with whom he became acquainted due to this incident, he heads to Rougetsu Island in pursuit of Ruka.