WATCH: Lady Gaga surprises class as substitute teacher

She's on a mission to teach kindness in a new PSA produced by Staples.

Here's a rundown from the video's description on YouTube:

Staples is thrilled to team up with Lady Gaga to support education and create a positive classroom experience through our Staples for Students program. We’re donating $2 million to DonorsChoose.org and Born This Way Foundation to promote kindness in schools and ensure teachers and students have the resources they need for successful learning in classrooms.