Chihaya's hobbies are generally listed as Musical Appreciation and Training.
I've become more interested in music since meeting Chihaya, and have learned more about reading it and the thoughts and terms behind it as well. She's mentioned liking classical, rock, and jazz, which I'm all fine with. I like j pop and other stuff too, but I'm fine with non vocal music as well.
As for training/working out, I'm not into that at all, but I'd be willing to do so for her as long as my initial slow pace wasn't too aggravating.
As for singing I enjoy doing so sometimes, but only when alone or casually as I'm untrained and sound horrible.
For my hobbies Chihaya's not really into anime and doesn't get the terms that well (she didn't know what tsundere and moe meant at first), but I could see her being interested in more musically themed series maybe. Same with video games, I think she'd enjoy rhythm games once she got the hang of it.
She's not really into TV which I think is understandable. She's not good with tech much either.
As for drawing I'm not too sure how she is with that.
I could see her wanting to study English when she goes overseas too.
Image unrelated, one of the more amusing out of context quote images I have.