Personally, if not the heroine, then Aoi taking the role of the love interest has immense potential.
I'm already noticing that:
The chapter where Aoi and Oga met is titled "Love Begins".
When they met for the second time, it was titled "The Man and Woman Who Met Again" followed by a colored double-page spread with Oga matching her outfit - that was the coolest spread so far.
And the continuing chapter, "The Second Meeting is Unavoidable Destiny"
I bet the whole school would be subdued if Oga takes his place as King and he and Kunieda would rule over the place.
GAR couple, anyone?
Well, I'd still say to take the subheadings with a grain of salt, I'm just pointing it out for the fun of it.
If nothing else, then I hope to see Aoi taking a central role as much as Oga and Hilde does, as Mentar mentioned, she is indeed an interesting addition!