Just a honest review from a regular anime viewer. I really don't know how some of the reviewers manage to write really detailed reviews so like I said it's just a honest review. To begin with, the story wasn't that special at all. There were funny moments and everything, but the story didn't had any fire or any hooks (I mean it wasn't that entertaining to watch (checked my facebook several times while watching it)).
On my opinion if you just stick to the main series and don't watch the OVA, you won't miss anything special and maybe save up some time.
Is it worth to watch ? Not really, but if you like Bakuon!! Then yes.
Story: 6
Enjoyment: 6
Overall: 6
*Spoiler*
Raimu Senpai saves the day like always.