The opening to the Kozama'uka night theme sounds just like Merry Go Round of Life from Howl's Moving Castle! Just the intros of both. And with Kozama'uka always raining, I can't help but think of My Neighbor Totoro :3

https://www.youtube.com/watch?v=DFiEjEiSXhE
https://www.youtube.com/watch?v=UwxatzcYf9Q

Also, don't you think the Pelupelu are a little familiar to a certain bird beaked race in Zelda Windwaker? Some even wear goggles too lol. FFX came out first though which first had the Pelupelu before Windwaker's Rito.

Funny that a while ago, there was a thing about how the theme of Sephirot phase 2 is so similar to When Worlds Collide by Powerman 5000.
https://www.youtube.com/watch?v=xdV_bzJgRxE&t=11s