oh yeah, no - from her perspective it's understandable. Bullying is a serious deal, and MC was the only one who stood up and tried to help.
But he also referred to the same incident as his "Dark Past" - which, bit of a meta call on my end from that term's usage in other titles, but that means it was such a cringe memory for him that he's actively tried to forget about it. To the point that she's hinted at why she's been so focused on him in an earlier chapter, and he just straight up didn't know what she was talking about in terms of "past events" that made her notice him.
That and he's so hung up on this fantasy relationship with her sister, that he's also never confessed to, and I just feel really, really bad for Kano at this point that he is the one she's chosen.
She's got a real Project on her hands, is all I can say.