4 episode OVA as a prequel to the TV


and a 2 episode ova sequel to the tv

http://anidb.ath.cx/perl-bin/animedb...ime&aid=73

http://anidb.ath.cx/perl-bin/animedb...ime&aid=90

http://anidb.ath.cx/perl-bin/animedb...me&aid=195