@Kireato
I believe Okubo's surprise was that in the first few moves of the match, Yumigahama appears to just be wildly monke swinging with no noticable skill and lots of wasted movements. But by the time Misasa approaches the edge, Okubo realises "oh, he was just fucking around because he thought he could immediately ring out Misasa," which is really Sandrovitch's way of saying "we haven't seen the limit of what Yumigahama can do."