It's hard for me to get past the relative thing. It seems like they'd perhaps be cousins? Which is just... ugh. What is with author's and incest? It wouldn't have changed the story at all if their parent's were just family friends. The fox was also a bit uncomfortable especially at the end stealing kisses and doing lewd things to try to 'help'. Ignoring those parts I enjoyed it so I'm just deducting one star for that.
Yakimochi wa Kitsuneiro