Well, after careful rereading of a good portion of the earliest parts of the manga, yes, my interpretation could very well be hard cope. It's probably her... how should i call it... overly friendly way of talking to him that made it seem to me as if she may have actually liked him. Though i wouldn't say that she discarded him after she found out the situation with him, she still maintained her overly friendly attitude, with a bit of teasing added.She was interested in him at first because he was an anomaly, someone whe couldn't figure out. She lost interest in him the moment she realised he was someone she had already discarded (read the chapters if you don't beleive me).
And honestly, rereading also made me realize how actually interesting Kusunoki used to be earlier in the manga. She wasn't anywhere near as bland as she seems to act now.