Here's why Grease's main characters Sandy and Danny didn't return for Grease 2. The 1982 sequel, directed by Patricia Birch (who had been a choreographer on the first movie) was rushed into production on the back of the original 1950s-set musical's success, but a chequered production story meant it was far from a perfect vision for a sequel. And while several original characters did return, the biggest names - John Travolta and Olivia Newton-John were nowhere to be seen.
Grease 2 may well have a claim to be one of the most underrated movie sequels of the 1980s, with some songs that rival even the musical numbers of Grease itself. Following newcomers Michelle Pfeiffer and Maxwell Caulfield as a second-generation Pink Lady and the English exchange student (and Sandy's cousin) who falls for her, despite their differences, it's very much a redo of the original's star-crossed lover story.
The fact that the two Grease films are so similar is partly why the sequel is so heavily criticized, but the idea of redoing the story with new players is far from unprecedented and if the original plan to have Danny and Sandy return, it might have been forgiven. Unfortunately, the planned cameo proved impossible, but why didn't Travolta and Newton-John return?
Grease 2 included no fewer than seven returning characters from the original (with five additional background actors also returning in new roles). Most notably, Didi Conn's Frenchy returned (but disappeared halfway through the film), and four Rydell High teachers - including Principal McGee and Coach Calhoun - came back. Eddie Deezen's geeky Eugene Felsnick also returned and so too did Dennis C. Stewart's Leo Balmudo ( otherwise known as Crater-Face), the leader of the T-Bird's rival gang. With all of those characters returning, it would have made sense that the leads would return for a fan-service cameo, particularly as the first plan for a sequel, called Summer School would have reunited the entire cast, had Paramount not passed.
Grease 2 director Birch wanted Olivia Newton-John and John Travolta to return for a cameo in the original ending, where they would be seen running a gas station. Olivia Newton-John has confirmed they were approached, while also confirming she didn't think much of the final product. Why they didn't appear is down to the change of plans: the cameo intended to bring them back never made it beyond the conception stage. Unfortunately for Birch, while John Travolta and Olivia Newton-John met with the studio to talk about returning, the pair weren't pursued further after that initial conference. Rather than reappearing for the sequel, Travolta went quiet for two years from 1981 after the underrated Blow Out while Newton-John was in the midst of releasing her twelfth album, "Physical" as Grease 2 was filming in the fall of that year. Neither was too busy, particularly, but it seems the plan for their tiny role simply wasn't right.