You're on the Compendium, consisting of one group (a whole lil community of gamers as it were), you're a group of people (unless I'm somehow misinterpreting the word "Circle"?) within that, thus 'sub-group'.
If you want to make a doujin, you can just make it and submit it. This is the point I'm trying to make; What is the point of this thread then? I'm not trying to bash the idea or prevent anyone from making Chrono-based doujin. It's just something happening in the forums that I do not understand (and would greatly like to if in fact there is anything to understand). I would say just as much, if not more because I'm wacky like that, if I had no mod/admin w/e.