[Wait really? Rin always looked so upbeat and energetic. It's a little difficult for Shu to imagine.]

I'm so sorry. Rin's nice and friendly. I haven't known him for very long.

But, I get the feeling that he's very important to you. [Shiemi cares so much about Rin. Shu almost shares the same sentiment. He's trying to speak as gently as he can. Rin and Shiemi must be going through a lot.]

You can make him happy. Just believe that you can.