All of them move with incredible amounts of fluidity. Going from a running jump into a somersault all looks very natural. The developers made sure not to mess this part of the game up. A method called interpolation was used to smooth out the movements of all characters. If you've taken a decent amount of math or used Excel, you probably recognize the term.
Interpolation basically calculates all the in-between movements given a beginning and ending point.
Rest assured that their movements easily rank up there with most of the popular fighting games currently out on the market. He didn't From what we've played so far, the game seems to run just fine. That is actually one of the things I really like about Oni. The walls all become transparent if you back up against them, conveniently solving the problem of bad angles or objects getting in the way. The walls turn into a very see through version of their normal selves, so it isn't as though there is nothing around you.