Kyoshiro to Towa no Sora

From Minna-scan: This is a story about a Kuu, who is thinking about her prince all the time, she has dreams of him all the time, of him telling her to come with her. One day, as she goes back to school, she meets with someone who looks like him, exactly. Not before long the story gets complicated with mechas and stuff, what will be of Kuu?