Based on the erotic game by Terios.

Five dangerous "seeds" have been stolen from their vault in the world of Evergreen and taken to Earth. Natsuki, an agent of the Queen, has been sent to retrieve them. However, he cannot do this alone and enlists the aid of Chihaya, a middle school student, who is "the only one" who can help him. With his aid she transforms into Magical Warrior Carmine in order to save the humans possessed by the seeds. Questions abound though, such as why Chihaya's mother appears to know all about this secret activity, why Chihaya remembers her father who reportedly died before her birth, and why she dreams of Evergreen, which she has never seen.

(Source: Anime News Network)