Okay, that was a little weird. Ash backs up from the girl a little more as she... growls? Hisses? Misty would sometimes seem like she was growling but she wasn't actually growling.

"Hey, wait!" Ash starts to try and chase after her to apologize since Pikachu doesn't seem willing to do so.

"Pikapia. PiKachu." He shakes his head firmly and Ash stops, just watching the direction she'd disappeared in.

"I wanted to at least say sorry..." He frowns.