Now I'm rewatching the trailer again in
there.I watched this trailer before the anime was started and now becoming more interesting =D the girl in the black feather looks so stylish.I think when Ereru and her sister are growing up and became like that.Ears and tails became shorter and feathers are came out.And the one who carried Ereru at the opening of trailer seems to be her daddy too.
[I think my spelling for Ereru is wrong but it's really painful to go back to previous post and copy,sorry]