Yeah, one of the things that is really fascinating about the book is that even though Kajii is for many ways bad for Rika, Rika's relationship with her also really allows Rika to open up her life to pleasure when she's really been living a pretty spartan existence.

I haven't read Natsuo Kirino, but after reading Butter I was thinking I should read more Japanese literature in translation (and feeling sad that none of Yuzuki's other works have been translated), so maybe I'll give her a try! It looks like the library has both of the books you mentioned. Which would you recommend first?