In The Mikado it's KAtisha. Which is just as well, because I'd otherwise have guessed kaTISHa, which is a very obvious sneeze. Hilarious play, very politically incorrect nowadays - plump elderly women are figures of fun and unsuitable for a happily married life, or any kind of married life actually. That said, I'd far rather be called Katisha than the beautiful soprano heroine's name - Yum-Yum!