First, about the video above: Urusei Yastura and I go a long way back. (That's right. I've got a 20-year-old cassette of Hirano Fumi singing Lum's song's too.) I was investigating Nana Kitade, and was just about to give up when I heard this little gem.
It's good to know that somebody else loves Bonnie Pink probably more than I do. (That's a lot of high grades!) But it's a promising starting point, and I'll have to see what else Lex recommends.
Bonnie Pink played at this year's Live Earth concert. I'm a sucker for a woman who can sing and play guitar (or bass (lest I neglect Aimee Mann)).
Edit: Removed a reference to a bad experience of mine. The internet can be a very dangerous place. Even YouTube can put you in a place you don't want to be. Tread carefully.
Edit: When I bought that UY music cassette in Japan, Nana Kitade hadn't been born yet. And here she's singing the opening theme...