She comes back to her alma mater (JFK Junior High) to perform a farewell concert before "retiring" to go to college. Student Zack (Mark-Paul Gosselaar) pretends to be dying in order to scam a kiss off her in a bet he made with Nikki (Heather Hopper). But Stevie is filled in on Zack's tricks by their teacher, the titular Miss Bliss (Disney's Hayley Mills), who Stevie is staying with, because obviously you can't expect pop stars to afford hotel rooms.
The kiss goes to the nerdly Screech (Dustin Diamond).
Stevie's real name is Colleen Morton (played by Suzanne Tara).