Nah there is a best ending for Shane. And as I said, it's my favorite ending. Such character development, especially since he seems to hate Hana in almost every other route. You're going to love it.
I've only gotten the best end and bad end with him, not even the good end and bad end. So confused by it to be honest. I have no idea how to get those two. If you want my help with the best end for any reason, just ask :) I'll be glad to help ahah