A certain prestigious academy... At late night, in the school building, one beautiful Holy Knight was fighting against a group of tentacles. She was Izumi Kanon. During daytime, Kanon was a normal high school girl. But during night, she changed into the figure of a beautiful knight who protected the academy. She spent her days fighting against demons and beasts to keep them away from the academy. One day, a beautiful girl transferred in Kanon's class. The name of the transfer student was Kagura Shouko. Unexpectedly due to chance, the two became close friends. However Shouko was attacked by a monster at the academy during night...Due to her close friend taken as a hostage, Kanon fell into a predicament. However, at that time Shouko awakened to the power of Holy Knight and changed into the figure of a beautiful warrior! In the end, what is the conclusion of the life and death struggle of the two female warriors---!?