I had such a hard time with Hayato's good endings (I kept picking the wrong answer in one of the beginning choices which threw off most of my playthroughs), but oh my god that was a good route. The first ending I got was the Reincarnation ending, and then I got the other bad ending, then like a never-ending stream of Hayato's normal ending before finally hitting the good endings. And man oh man, those good endings were good. I don't wanna spoil anything for anybody who might be reading this comment, but I especially liked the more evidently bittersweet quality of the good ending where she had to return to the human world. I thought it really highlighted the character development of both MC and Hayato (but especially Hayato). I dunno. It could also be because I am partial to the thought of fantastical/supernatural creatures living among humans in the human world.
On the whole, though, Good Job!! Hayato's route was great, and I can't wait for the other routes to come out :D