I've always loved the Hero/Partner dynamic in PMD games, and to be honest they always felt more romantic than just good friends. So I took that concept and added in a few things that I personally enjoy. Then I decided to pick a pairing that (I thought) there were little instances of, plus Shinx and Vulpix are easy to draw for me. So it was a number of things, but all in all I'm very happy with how it turned out so far!