Rias Stadtfield attends an ordinary school, has ordinary friends and lives an ordinary life. Nothing special about it - she goes through typical days, months and years. But all of that changes after Rias has an extremely lucid dream about an elderly guy cloaked in constellations. The grumpy man informs her that he is Lord Cosmo - protector of the Zodiacs, twelve demi-gods scattered across Earth. Her dream so is out of the ordinary and confusing that she forgets about it completely and wastes no time in slipping back to her ordinary days....until a turn of events causes her to realise that everything the man had said was very much real. The man is dead. Lord Cosmo is dead. And who is next in line to protect the Zodiac siblings? Rias Stadtfield: the new Lady Cosmo. Armed with nothing but a moonstone pendant and little to no information whatsoever, Rias is forcefully shoved into a world of magic, stars, and aliens threatening to start an intergalactic war unless she returns to them what the Zodiacs stole millenniums ago.