A reclusive writer, and lover, of mystery novels. She may or may not be a projected version of Featherine Augustus Aurora.
Ikuko finds an amnesiac Battler Ushiromiya on the side of the road, following the murders on Rokkenjima. She renames him Tohya Hachijo, due to him only remembering the fact that he was 18 years old upon being discovered. After learning about Sayo Yasuda's forgeries, she ghost wrote novels based on Tooya's attempts to remember the Rokkenjima murders. These novels then became the framing device for Episodes 3 through 6.
