Lady Gaga continues her ongoing kindness crusade, this time in partnership with Staples, stepping in as a “substitute teacher” recently for a group of surprised kids in Los Angeles.

The pop superstar and frequent brand collaborator appears in a PSA with middle schoolers that serves a dual purpose: She’s promoting a positive and accepting environment for youngsters, which she says “makes it easier for kids to learn,” and launching a fundraising campaign for her Born This Way Foundation and DonorsChoose.org, which helps teachers pay for classroom projects and supplies.

Staples, which is Gaga’s title sponsor for her Joanne tour, has already donated $2 million to the causes. Through its Staples for Students program, the marketer supports educators and addresses research that has uncovered stats like this: Some 99.5 percent of public school teachers use their own money for supplies, to the tune of at least $400 a year.

Along with the PSA, which debuted this week and will air across national TV, digital platforms and social media through the back-to-school season, the retail giant is running a contest that will give away a $50,000 scholarship and a trip to Las Vegas to see a Gaga performance and meet the singer-actress-activist.

Sixth and seventh graders at Walter Reed Middle School in Hollywood had no idea they were getting a visit from pop royalty earlier this month. Most recognized Gaga immediately when she walked through the door in a stylish electric-blue pantsuit. Cue squealing, hugging and crying.

But a few had to be convinced she wasn’t a lookalike. “Are you the real Lady Gaga?” one student asked. “Yes, it’s me,” she said, taking off her black-rimmed smart-girl glasses to better show her famous face.

There was no script or storyboard for the shoot, which comes from Madison + Vine, because producers wanted to allow Gaga “to be flexible and add her authenticity to the piece,” said the agency’s CEO and founder, James Shani. She asked the kids about their goals and dreams, for instance, and had them sit in a circle and act out their “future selves.”

Staples, a longtime advocate and donor for public schools, dovetails its efforts with Gaga’s Born This Way Foundation, devoted to wellness and empowerment of kids and young adults. Working with Starbucks on colorful limited-time drinks, Gaga recently raised $250,000 for the nonprofit through the #CupsOfKindness initiative.