Based on the third game in the Harukanaru Toki no Naka de universe, Kurenai no Tsuki take on a whole cast different from the Hachiyousho series.
Nozomi Kasuga is in her 2nd year of high school when she meets a strange boy who sends her across time and space to Kyō, a world vastly different from her own. There Nozomi discovers she's been chosen as the Hakuryū no Miko (Priestess of the White Dragon God), and she must find a way to end the war between the Genji and Heike clans before the Hakuryū can send her home. Adding to her problems is a bunch of attractive young men with different agendas to deal with, and in the meantime, the Heike clan plot to release onryō throughout the land...
an extended description!