With his marriage decided, Akio Koga returns to his hometown to share the news. As he feels a wave of nostalgia for the town, he is also reminded of Akira Misawa, a girl who disappeared back in high school. Akio has long been haunted by the thought that Akira’s disappearance might have been partly his fault. He reunites with Yuiko Oshiro, his homeroom teacher from high school—now a novelist—but… A girl who vanished without warning one day in the past. A man who, after a long time away, returns home and meets her again. Is she truly the same girl from back then? Or is she merely an illusion shown by the guilt he’s carried all these years? The more he tries to unravel the deepening mystery, the stronger his anxiety grows. Where will he ultimately arrive—and what awaits him there?