[@Ammokkx] I just noticed a very slight similarity between Ethel and Shinrei. Took me awhile to pick up on this when you said Ethel has emotions and she showed it to her plushy. They both convey their emotions through something else. Ethel's case it's that rabbit and Shinrei's case it's his own sister. Don't know why it took me so long to pick up on that one, but I did noticed that Ethel is human when she wants to be like Shinrei.

Edit: And I didn't think they shared anything in common...