I agree with aquanoun--"fictional-looking" is exactly what I thought. To me it looks like something out of
Star Wars because of the "Oo" at the beginning (I think there actually was an alien named Oola in
Star Wars).
At first I couldn't understand how someone could like this name, then I saw one of the posts mentioning
Una and realized it was the look that was putting me off. The sound is nice, and I like it with the spelling
Una; I just couldn't get past the "sci-fi" look of
Oona.