Aya Mikage and her twin brother Aki go to their grandfather's home for their sixteenth birthday unaware that it's actually a test to see if they have enough angel or celestial maiden blood in them. Aya is the reincarnation of a powerful celestial maiden called Ceres. When she transforms into Ceres, Aya obtains supernatural powers and abilities such as flight, teleportation, telepathy, incredibly strong and powerful telekinesis, premonition, projecting powerful and destructive deep pink glowing energy blasts from her hands, creating incredibly strong and powerful impenetrable shields and barriers of pure deep pink glowing energy, and superhuman speed. According to the legend, Ceres will kill the Mikage family for revenge upon stealing her celestial robe, thus preventing her returning home to Heaven, so Aya's family attempts to kill her. However, she is saved by Suzumi Aogiri, another angel descendant with supernatural powers, (since not all Mikages have angel blood) and Suzumi's brother-in-law, Yūhi Aogiri. Aya tries to control Ceres's power over her and Aki is taken over by the vengeful hateful spirit and soul of "Mikagi", the ancestor of the Mikage family who first stole Ceres' celestial robe, forcing her to stay on Earth. Aya also wrestles with her growing love for Toya, a servant of the Mikage who is trying to kill her, but lost his memory of his past. He also starts to love Aya in return. Aya promises Ceres to help her find her celestial robe in exchange for not killing her family (especially Aki) who hunts her down, since Aya still loves them. Toya tries to regain his memory. He learns that he was the organism that Ceres's celestial robe (otherwise known as "the mana") created to help it reunite with Ceres.