Kisame isn't surprised when Rui starts slowing down. It's a little disappointing, but he thinks she stayed with him longer than she would have when they first met. It means she's getting stronger and it is heartening.

So when she waves, he turns around and gives her an approving nod. "I look forward to our spar, Rui-san."

Then he continues on, smiling and quickening his pace, because now he wants to push himself and be at his best when they spar. It will be exciting, that's for certain.