Kujou Sakurako is a beautiful and talented osteologist, or bone specialist, whose life is centered around bones only. Sakurako has little tolerance for illogical behavior and a lot of trouble understanding other people; she would be isolated in her study full of skeletons if not for her assistant, high school boy Tatewaki Shoutarou, who does his best to drag her out and make her interact with others. And yet, whenever they go out, the dead seem to be around the corner, because the two of them often stumble upon human skeletons or corpses.