the individual kanjis mean - strike, open.
but according to jisho.org when combined it means
だかい - dakai - 'break in the deadlock'
so maybe this is an indication of a successful counter attack. ie. the opponent grappled Ryo and he successfully executed a strike reversal.
Great theory!
best to wait for the switch translation.
Haha, well you guys have already nailed the meaning of the characters. I did manage to discover a couple more links with Bajiquan which you may find interesting. The research took longer than I expected, there wasn't a lot of easily-available information on it.
Link to post: http://www.phantomriverstone.com/2018/07/examining-warehouse-battle-scene.html
https://i.imgur.com/IYO7mKFl.jpg