Sounds good to me.
It could be based on the Russian fairytale which also has Greek and Italian versions or a variation of Grimm’s “The Frog Prince”.
Russian “The Frog Princess”
http://www.lacquerbox.com/frogprincess-long.htm
Brothers Grimm “The Frog Prince”
http://www.authorama.com/grimms-fairy-tales-12.html