This OVA is only recommended for people who already saw and liked the main anime; if you didn't there is no reason for you to see this one. This anime is an old comedy nonsense and made to promote a certain store from Akihabara. That means the story is nothing but relaxed and focused to make you laugh, don't expect a drama. The art is kinda bad even for an old anime but I think it is done on purpose, it helps build the mood.
The music on this anime is as good as the previous. The use of another variant of the sticky song "party night" is a safe decision but there is nothing new. The voices are acceptable or at least there wasn't anything that drag the anime down. Every important character from the anime makes an appearance that can make the fans laugh.
This OVA is done for the fans. Personally, I saw the anime a long time ago and this bring a lot of memories from the anime. The humor is somewhat relaxing and meant for everybody to just sit and relax a couple of minutes. Since this is that kind of anime I give it an 8, because it is very good but not near great.