They werent assaulting her, they were asking for her advice, and he only though that they were confessing to her, not trying to assault her, there were girls also in the line, so your logic kind of does not apply in this situation.
what most likely happend was that he told her he will confess to hikari, she kissed him, he pushed her away and then we have what happened last episode
He likes marika, he thought she liked him to some degree ( she does a lot) but seing her broken meter confused him and he is trying to get her to like him before confessing because he thinks dhe secretly hates him.
Just because another girl likes him doesnt mean he will give up pursuing...
Bitch, if a male character did something similar to what shiori did here, i would like to have him forcefully raped by horses before having all of his skin ripped off and then dismembering him. We would react even worse if it was a male character
Last chapter literally showed her doing homewrecking in the past. She BECAME a FILTHY whore. Not because of her body , but because of who she is as a person