Yoko enjoys her single life as a successful author. Yet since childhood she has had a recurring  dream in which she is an unhappy housewife with a husband and child who make incessant demands on her. As Yoko puts it: “The self in my dreams has been growing up at the same speed as my real life. So she seems to be going through life at the same pace as I am, but in a different place and time—as if she lives in a parallel world.”

But now, incidents begin to occur in which the disparate lives of the two Yokos grow increasingly entangled. As her real and dream worlds converge in disturbing ways, Yoko finds that both of her selves appear to be the target of murderous intents. Jumping back and forth between the two Yokos—“Side A” and “Side B”—the narrative races to a stunning denouement with an unexpected twist. The reader is left to savor the satisfactorily queasy aftertaste that makes this novel a masterpiece of the iya-mys genre of “creepy mysteries.”