Warning, this scene is intense. The girl being KO'd is the one wearing a baseball cap and miniskirt. An intense sequence begins near the end of the volume, where the girl is beaten up by a gang of strong guys.
Her friend tries to stop the guys, but it's no use as they are able to hold her back.
The climactic scene shows the girl on the ground getting punched in the belly by a really strong dude. Don't worry though, she amazingly survives this abuse.