Spider-Man: Homecoming stars surprised 500 high school students Tuesday to kickoff an anti-bullying PSA

You never know when a favorite superhero might be lurking nearby — or the actors who appear in their movies.

A group of lucky high school students in New York City learned that very fun lesson Tuesday when Spider-Man: Homecoming stars Laura Harrier and Jacob Batalon — along with a backflipping, selfie-taking costumed Spider-Man — surprised 500 high school students in an assembly to launch an anti-bullying public service announcement (PSA). The actors, who play high school students and friends of Peter Parker (Tom Holland) in the summer blockbuster, encouraged the students to practice the movie’s message of “celebrating the differences between people.”

“I think Spider-Man: Homecoming is all about celebrating the differences between people and showing that that’s what makes us interesting and special,” Harrier told PEOPLE at the assembly, Tuesday. “We talked a lot about the message of just being who you are and embracing who you are.”

Credit: Billy Tompkins/Sony Pictures Home Entertainment

The event was a collaboration between the Homecoming cast and nonprofit STOMP Out Bullying for the debut of their PSA, which includes Holland and costar Zendaya, in honor of National Bullying Prevention Month in October.

“The movie is so real. It’s about real life, and I think it’s incredibly exciting,” said Ross Ellis, founder and CEO of STOMP Out Bullying. “The more we get out there to the kids, they’re going to stop this. They’re going to change the culture, and they will eventually stop all the bullying.”

Many of the film’s characters don’t fit into the stereotypes typically portrayed in movies about high school students. Harrier’s character, Liz, is the most popular girl in school, but also captain of the Decathalon team. Unlike the way many “popular kids” are often portrayed, Harrier said her character is kind and friendly to everyone.

Credit: Billy Tompkins / Sony Pictures Home Entertainment

In Homecoming, Parker and his best friend Ned, played by Batalon, are both considered nerds.

“Ned is not the most popular person, [neither is] Peter, but the message is that it’s okay that they’re like that,” Batalon said. “The best version of themselves is being the nerdy kids, and being friends with Laura [Harrier]’s character just proves to the whole point: You don’t have to be a jerk to be cool, you don’t have to be a jock, you don’t have to be the head cheerleader.”

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For the students of the High School of Fashion Industries, the entire assembly came as a surprise. After being called to their high school auditorium, the teens were ecstatic to learn that cast members from Homecoming were there.

Batalon and Harrier were excited too. Batalon stopped his speech to take a selfie with the 500 students, and candidly admitted that he was nervous and “not a very good public speaker.”

But after viewing the anti-bullying PSA, the students received yet another surprise. All heads in the room whipped back toward the entrance of the auditorium to see none other than their friendly neighborhood Spider-Man himself, who came in running, jumping and doing flips off the auditorium seats.

The costumed web slinger moved into the audience to engage with students and sat down next to a very surprised Amber Rose, 17, and took a selfie with her — then suddenly everyone wanted a picture.

The event’s special guests encouraged students to participate in STOMP Out’s anti-bullying campaigns this month by wearing blue on Oct. 2, in support of the World Day of Bullying Prevention. They also asked them to block cyberbullying posts they see on social media.

Student Tymera Parker, 17, was moved by the assembly. Parker said she witnessed a bullying incident in the school’s cafeteria the day before the event, and is proud that one of her friends intervened to make it stop.

“I’ll be loyal to the cause and I’ll wear blue from head-to-toe because I had experiences with bullying,” said Parker. “I’ll also tell my family and friends to block out the posts with people making fun of other people.”

Credit: Billy Tompkins / Sony Pictures Home Entertainment

Another student, 16-year-old Allana Ragler, plans to use her social media for good in addition to blocking negative posts. Ragler said she will spread awareness of the anti-bullying campaign by posting on her accounts.

“I think most people have experienced some form of bullying. I remember how it was when I was in high school,” Harrier recalled. “I feel like kids in high school now are just really aware and socially conscious in a way that previous generations haven’t been. And I think it’s really awesome how they’re excited to partner along with this, and how they want to change the culture of bullying and start to take care of each other.”

Spider-Man: Homecoming is now available digitally and will be released on Blu-ray and DVD October 17.