Who does Kazuma really end up with?

I keep on getting people telling me that Aqua was the one who won and not Megumin.

WN pic IIRC

As far as I know, vol 17 is not fully translated but we do have the synopsis of it and it was stated that Kazuma and Aqua have a platonic relationship. Who does Kazuma really end up with? Does the synopsis posted here and from the wiki really give us a clear insight into who won?