In this scene, Yui has to hit Withit over the head with a beer bottle. Yui said that it was hard for her because she was afraid for Withit, but she was able to do it.
From Channel 7 Online. Translated by Noiki
Yui has to hit Withit on the head, one take only
Yui: When the director said 'Action' I had to really hit him, but I was afraid because I was too excited even though I wasn't the one being hit.
Withit: At first I was okay, let's do this, so I gave her the green light to go. But then I started to get scared and it was more like a yellow light now.