There are no costs, and the only requirements to join a fanlisting are your name and country. Fanlistings do not have to be large sites (although some are), they are just a place where you can sign up with other fans. TheFanlistings.org is the original (but not official) web directory for fanlistings, dedicated to uniting the fans.
Description from tfl.
kyoshiro to towa no sora
I'll probablty build a fan-site for Kyousora in the near future, at soon as the anime serie will be finished. I'll try to make a comparison, in this way, of the anime and the manga. Anyway for now, here you are a short intro:Kyoshiro to Towa no Sora revolves around the life of Ku Shiratori who is a seemingly normal high school girl who enjoys school life in the giant city Academia, which is thought of as a symbol of recovery for humanity since already ten years have passed since the greatest disaster mankind had ever seen occurred. Ku has recently been having a recurring dream where a prince meets her and takes her away. One day, while all the students at her school are preparing for the upcoming school festival, the prince whom she has met several times in her dreams appears. The prince, whose name is Kyoshiro Ayanokoji, requests of her just as he had done in Ku's dreams, "Let's go...together..."
Source: wiki.