[Bon is quiet for a long while, thinking about what Rin just said. It's nearly half-a-minute later before she finally speaks up.]

I'm...I thought you were just a loser who didn't belong in the cram school. I thought you'd gotten in by buying your way in, or something, and that you didn't really give a shit about learning anything.

[It's not quite an 'I'm sorry,' but the tone shows that she knows her assumptions were at least partly wrong.]