Kei mentions he worked with Mafuyu under Junsei Takamine, but he has an interest in researching folklore. While looking into the disappearance of his niece Mayu, whom he suspects has been 'spirited away' like Takamine, Kei comes across the Camera Obscura in a house in an unnamed, small village that isn't listed on any maps. The camera seems to have a negative impact on his niece Mio, who appears frightened and distressed by it. Kei sends the camera to his friend Yuu Aso for safekeeping. Soon after the discovery of the camera, Kei's niece begins to sleep more and more, and complain of nightmares. As Kei researches into the cause of Mio's affliction, he realizes that Mio's symptoms are similar to those mentioned in the 'House of Sleep' urban legends. Kei continues to write to Yuu about his findings, as well as asking for help, unknowing that his friend has died in a car accident.
As Kei researches more, he too begins to show symptoms of the curse, including having nightmares of a strange tattooed woman, and wonders if he is cursed or has merely been working too hard. He sees Mio in his dream, talking to herself and blaming herself for her sister Mayu's disappearance.