lol yea its one of the anime sibling relationship stereotypes we have here.
Imouto being the mature one while Onee-chan being the not so mature one
usually I think this type of thing is only really done ok most of the time but I really like it here. Ui comes across better than most Imoutos in this case which I think makes it work alot better.
I never realised this before till after watching K-On but I have a similar one with my wee sister
