The trailer for the 1977 London-set “How to Talk to Girls at Parties” begins with Enn (Alex Sharp, Marti Noxon’s “To the Bone”) and his friends attending a concert’s after-party. Hoping to meet some girls, the three punk music lovers encounter Zan (Elle Fanning) and her cohort of orange leather-clad, six-fingered, monotone friends. “They must be from California,” Enn’s buddy guesses. He’s not that off: Zan and company are actually aliens from outer space.

Zan and her fellow extraterrestrials, including Stella (Ruth Wilson, “The Affair”), are visiting Earth a rite of passage — but Zan is bored and ready to break away. In frustration, she cuts up her futuristic dress with a pair of scissors. “Do more punk to me,” she says as she hands the scissors to Enn.

Enn is happy to introduce Zan to London’s punk scene, as is its leader, Boadicea (Nicole Kidman). In punk music you have to “smash the oppressor, tell the truth, be an original, blah blah blah,” Boadicea explains to Zan. And as she falls more in love with punk culture and Enn, Zan realizes she’ll eventually have to speak her truth and choose between Earth and her own planet.

“How to Talk to Girls at Parties” is directed by John Cameron Mitchell (“Hedwig and the Angry Inch”), who penned the script with Philippa Goslett (“Little Ashes”) from a Neil Gaiman short story. Mitchell previously directed Kidman in the 2010 drama “Rabbit Hole.” “How to Talk to Girls” made its world premiere earlier this year at the Cannes Film Festival. It opens theatrically in Japan on December 1, but doesn’t have a U.S. release date yet.