For me, as to why I find this OVA interesting is the author's use of the harem, I guess this OVA is more like a continuation for the other members of the harem to be able to be with the muchacho (lead male character) , though Manaka was was able to have another supposed opportunity to be with the muchacho (that's in OVA1), but you know, what really do make the story of this OVA good (including the anime itself) is the authors well use of the genre's, so I here by give it an 8 for the story.
The art itself is fairly good (6)
and so as the sound (6), the characters role kinda represent a different genres, but the main point of it all is the muchacho who is represents a kind hearted soul which every members of the harem connect with, so I rated it as an 8. The enjoyment is very good and the author really defined the the phrase "FOR GENERAL VIEWING" which can be viewed by all ( as long as you forget the panty shots).
Overall, I thinks the author of this anime should have made a season 2 instead of a couple of OVA's. So, at this point we can only hope. (my overall rate is 8)