A girl wakes to find she has been summoned by an Onmiyouji who informs her that she is his shikigami — his supernatural servant, created to do his bidding. She has no memories, but an instinct that she used to be human and that her name is Sayuki. Her new master, Abeno Seimei, is demanding: accept the role of shikigami, or disappear entirely. Sayuki accepts and is put to work in the capital city of Izumi — consoling quarreling couples, delivering love letters on behalf of clients, and occasionally, fighting demons.