@LastGlance Yeah it's her. I see your point, but for some reason I get a feeling the author might take it another direction. I could be wrong, it's not really an opinion more so a possibility. My thought is that likely she talks about her time with Yeoreong with her friends and they are the ones instigating the rumors and riling her up by making Dan-I look bad and using Yuri as a pawn to separate Dan-I from the 4 kings. Yuri's friends glare and are angry at the others for being close the the 4 heavenly kings, but Yuri is only angry because she thinks the rumors are true, she doesn't seem to care at all about the kings. At least that's how I see it so far.
She is also defending Dan-l initially by saying they don't have the evidence in page 3, then she says she will bring it up with Yereong and her "friends" have a slightly ominous smile when they say she should probably bring it up. I think Yuri is being used.
Also one last point, it's Yuri's friend that saw the post on the bulletin board. She is likely the one posting if she is the one hanging out in such a hateful board.
Of course I could be completely wrong, but that's the feeling I get after this chapter! Time will tell, it's up to the author in the end.
I will wait judging Yuri until we know more, so far she seems like a hotheaded but honest person. Her friends are pure trash though.