This anime already came out on the 23th, but before today I didn't had the chance to check out the first part. As mentioned before this is a reverse harem anime playing in a school that just recently got co-ed, with only one girl.
What surprised me some is that this isn't from the view of the girl, but the boys - probably one-by-one.
First is Capricorn, the red-head Tomoe Yoh, his connection with Yoshisa Tsukiko, and their re-meeting.
From the story I would say the title is cause "the sky connects us all together" and the school is all about constellations, star-gazer and other fortune-teller.