North Shore High School is an American High School in Evanston, Illinois. The school is where the main casts of the film Mean Girls and the made-for-tv movie Mean Girls 2 attend. This High School does not actually exist but is based off of New Trier High School in. Oct 3, - Four former mean girls tell their stories and share their regrets and how they've changed. Spoiler: they've grown up a lot since high school.