p.s. A relationship chart for this series would be very similar to that of one of writer Kitagawa Eriko's first dramas, Asunaro Hakusho (あすなろ白書 ), which, in actuality, is an adaptation of a pretty well-received manga.
Oh, and unrelated (and kinda sadistic, I suppose, considering the above), but Durarara!! author Narita Ryougo-sensei shed tears at Angel Beats! episodes #3 and #10!!
And while we're on the subject of DRRR!!, I finally got round to watching the Dengeki Stage Fest 2009 event (it's available on the first DVD, if I remember correctly), and boy is it hilarious! Highlights: HiroC, OnoD and JunJun ribbing Toyonaga Toshiyuki, and a certain surprise guest ^^
And for anyone who wants to check out a Butler Cafe, the one on Otome Road is called "Suwarouteiru" 「スワロウテイル」. Hm...if I didn't know better, I'd guess "Swallowtail",