The year is 1853, and a young Japanese girl's world is about to be turned upside down.

When black ships carrying barbarians arrive on the shores of Japan, the Satsuma clan's way of life is threatened. But it's not just the samurai who must come together to fight: the beautiful, headstrong Okatsu is also given a new destiny by her feudal lord - to save the realm.

Armed only with a new name, Princess Atsu, as she is now known, journeys to the women's palace of Edo Castle, a place so secret it cannot be marked on any map. Behind the palace's immaculate façade, amid rumours of murder and whispers of ghosts, Atsu must uncover the secret of the man whose fate, it seems, is irrevocably linked to hers - the shogun himself - if she is to rescue her people . . .