Nana to Japa

My host sister (Karen) came home really late today...with a sprang ankle from track.
She's like the track star or something.
When I was a school and people asked me who I was living with...when I said Karen-chan all the lights switched on and everyone was like oh my gawd! Karen Tani-san?! What's she like? Is she nice to you? Etc...lol.