When Aya Mikage, a high school girl, celebrates her sixteenth birthday, a hidden truth is revealed. According to a legend that is passed on for generations in the family, the founder of Mikage fell in love with a Goddess, Ceres, and stole her precious plumage that had the power to carry her back to heaven. Ceres, who was trapped on Earth, had no choice but to marry the man. Ceres swore that she would destroy the whole family.
Now, when Aya's family realizes that the spirit of Ceres is hidden inside of Aya, they turn upon her with sudden ferocity. With her life at stake, the spirit of Ceres hidden inside of her awakes and saves Aya. After this, Ceres appears to Aya frequently, occupying her mind. Determined to uncover the mystery, Aya set off on a quest to find the plumage.