Just watched the OVA, which can be found
here, and I have to say, it was pretty fucking terrible. It's a totally original episode (unless you count the one part where Tsubaki's sister get's naked, which did happen in the manga) where Tsubaki and Ueno go to the summer festival, but Ueno invites Oka and Urabe to make it seem like they're just hanging out. The thing that really kills it is that Urabe really doesn't feel like Urabe, her attitude completely changes at the drop of a hat and the actually "plot" of the episode is just plain stupid. One of the main strengths I find with MGX is that the situations are crazy and zany, but still believable, this was in no way believable and I found my self just staring at my screen going "What the hell were they thinking". Overall, pretty bad, but watch it anyway, just because this series needs more love. Also, for the record, I only mean the OVA, the TV series was pretty good and you should go watch it if you haven't already.