"All She Was Worth"

I mentioned Natsuo Kirino's "Out" recently, saying it was the first modern Japanese story I'd both enjoyed and felt I understood. Miyuki Miyabe offered me the second in "All She Was Worth". It wasn't as well written as "Out", at least to my western eyes: it was far too didactic at times, stopping with a screech of brakes to explain things at length. Nice ending, though.

I wonder why the original title was "Kasha"? What does that mean?