Ouran #11 is quite satisfying. I liked the wacky hijinks, but I wanted more of the love dodecahedron, and #11 delivers.

On Nana #15, I was quite interested in the whole fanclub subplot, but we only got a sliver of that. We also got another sliver of the 'in the future' scenes. Shinji and Reira's relationship is shown beautifully here.