 The story revolves around Kōhei Orihara, the main protagonist. His father died when he was very young, followed by his younger sister Misao and finally his mother. Deeply depressed, he goes to live with his aunt Yukiko, his mother's younger sister, about ten years before One's story begins on November 30, 1998. After he meets Mizuka Nagamori as a child, Kōhei begins to seclude himself in the Eternal World, a world within his mind. The game's main recurring motif is a focus on the Eternal World, a mystical alternate space which is never clearly explained, and the details of which are unknown. Shun Hikami's remarks in the original game are possible clues about the Eternal World.
