Ah, sorry! Been recovering from throwing up the past few days, but Nanao!

Dear, sister! That's what she is to China~ He feels that he can make quite a few connections to her since they've both lived for a long time and Nanao knows his world's history (which saves a lot of explaining to do).

China also admires her strength to go on all these years. If she were to compliment his own, he'd try being humble at first.