BD 6 cover
As expected, the cover is Maho& Erika
6th OVA name is [エンカイ・ウォー！] ("Banquet War!" - Google translation)
OVA about Oarai's victory celebration???
Edit:
Each team status from the Booklets in BD 2-4 ( I don't have the first's)
http://i.imgur.com/5PYpEWP.jpg
http://i.imgur.com/jyyRBLe.jpg
http://i.imgur.com/YzINuF6.jpg
Card from BD 2-4 ( I don't have the first's)
http://i.imgur.com/bC1gOCv.jpg
http://i.imgur.com/DfQXsAg.jpg
http://i.imgur.com/1hhWlay.jpg