Okay, so first I apologize that I couldn't find the actual clip from the show. If someone else finds it in an embeddable form, I'd gladly switch it out.
And of course, the song is about Lisa, not Risa (though if Risa were a Simpsons character it would totally be Lisa...or maybe that guy in a bee suit.) Anyway, you could either do a mental find/replace and sub in Risas for the Lisas (or Liza!). Alternately, you could assume that the vocals are doing distasteful imitations of Asian Americans (remember all those "flied lice" scenes in A Cricket in Times Square?)
Anyway, happy birthday L'Risa