Qin Youbei's nature was that if you didn't provoke her, she wouldn't provoke you, but if you went too far, she'd undoubtedly not let it go.
As for Xiu Huihui, let it be, since she had already received severe punishment, but Liu Siyue never admitted guilt till the end.
Although in the end, it hadn't been proven that Liu Siyue was the one who had enticed others, that didn't mean Qin Youbei believed she was innocent.
Qin Youbei was one hundred percent certain that the mastermind behind this incident had to be Liu Siyue, because Xiu Huihui didn't know her at all. If it wasn't for Liu Siyue's instigation, how could Xiu Huihui possibly have framed her?
She believed no one would go out of their way to frame a stranger for no reason.
If the school couldn't punish her, then she would take matters into her own hands.
There was no need for any cunning plots, Qin Youbei directly sought out Liu Siyue, and without a word, she fiercely slapped Liu Siyue's face.