Bishop no Wa

Demons are haunting Kana in her dreams. Kana and Reiji, who attract demons, break the ancient seal and release a hundred demons loose. The guardian of the demons Bishop has punished the two. When the sun rises, Reiji becomes a horse, and when the moon rises, Kana becomes a bird. The only key to lifting the curse is to stop all the hundred demons and seal them away.

(Source: Shogakukan, translated)