It's a little awkward of a way to say it but Kisame is able to put together what Naoki wants. He lets a couple bubbles of air escape his mouth in a signal for laughter and gestures to the shark. She returns to his side, to swim in a slow circle around him, so she can use her gills properly.

Kisame then signs 'yes' back at Naoki, then 'watch.'

He demonstrates how to do it so that her denticles won't tear or otherwise damage skin, and then gestures for Naoki to come closer so he can try for himself.