Harukanaru Toki no Naka de 3

On an ordinary rainy day, high school student Nozomi Kasuga and her two friends encounter a strange boy at school who opens a gate in time and space without warning, sending all three of them to a place called Kyō — a world resembling Kyoto at the end of the Heian period, where the Minamoto clan is at war with the Taira. The Taira are attempting to tip the war in their favor by releasing vengeful spirits — onryō — that disrupt the land's natural energy and terrorize its people. The strange boy reveals himself to be the human form of Hakuryū, the White Dragon God who protects Kyō, severely weakened by the onryō's presence. Nozomi discovers she is Hakuryū no Miko — the White Dragon Priestess — with the power to seal the onryō. She allies with the Minamoto, works to restore Hakuryū's strength, and searches for a path back home.