
Can someone please help me understand what has happened between those two in the past? Hwa and the female lycan guy. And why do I feel like Yibin and hwa gok don’t like the female lycan guy?

Seolhyun tried to run away from the lycan master and Hwa helped him, but they got into an accident instead. Because of that, Ino had to erase Hwa's memories. It's not like they dislike Seolhyun but they just don't want Hwa to get hurt again. The lycan master does not like Hwa so he'd really be in danger if he'd continue to be with Seolhyun.
Asada is a jerk and the pink hair guy is just pitiful.