Harukanaru Toki no Naka de 3 Ultimate

On a rainy afternoon, Nozomi Kasuga and her two friends are pulled through time and space by a strange boy to the world of Kyō — a place resembling Kyoto at the end of the Heian period, where the Minamoto and Taira clans are locked in brutal war. The boy is Hakuryū, the White Dragon God of Kyō, whose powers have nearly failed because vengeful spirits are disrupting the land's natural energies. He needs a Miko capable of sealing them. Nozomi discovers she is that person, allies with the Minamoto, and sets out to seal the spirits, restore Hakuryū's strength, and find a way home.