They had to be careful in filming this action scene between Yui & Withit because Yui has to give it her all in kicking him. But before, both stars rehearsed it well so it only took 1 take and it passed.
From Channel 7 Online. Translated by Noiki
Yui & Withit during their action scene
Withit: I have to dodge quickly, but accidents happen sometimes. I think Yui hit me a few times.
Yui: For the kicking, I had to do it for reals and I'm pretty sure it hit him.
Withit: It's because if we didn't do it for reals it would've taken a lot of takes and by then it wouldn't be as good.