Aya Mikage and her fraternal twin brother, Aki, are forced to go to their grandfather's home for their sixteenth birthday, unaware that it's actually a test to see if they have angel or celestial maiden blood. Aya learns she is one of many reincarnations of a vengeful and supremely powerful celestial maiden named Ceres who takes over her mind and body only under intense stress or fury. When she transforms into Ceres, Aya obtains supernatural abilities of flight, teleportation, telepathy, powerful telekinesis, premonition, and superhuman speed; she can also project destructive pink energy blasts from her hands, and create impenetrable shields of bright pink-colored celestial energy. According to myth, Ceres will ultimately exterminate the entire Mikage family in retaliation for stealing her hagoromo (celestial robe), thus preventing her returning home to Heaven. Because of this, Aya's paternal grandfather and his party attempt to kill her, but she is saved by Suzumi Aogiri, another descendant of a heavenly maiden with incredibly strong celestial and mental abilities of her, and Suzumi's brother-in-law, Yūhi. Aya struggles to control Ceres' infulence over her and appease her spirit once and for all. Her brother Aki is eventually completely taken over by the vengeful spirit of "Mikagi", the original ancestor/progenitor of the entire Mikage family who stole Ceres' celestial robe (or "mana"), forcing her to stay with him on Earth. Aya promises Ceres that she will help find the celestial robe in exchange for not killing those who hunt her, especially Aki, since Aya still loves them as family. It's revealed(in Episode 7, "Celestial Awakening") that "The Hagoromo Legend" not only exists in Japan, but in other countries around the world such as Europe, Africa, all three regions of Oceania, Germany, China, Korea, Russia, and even all fifty states in the United States...