Superstar is about a girl named Mary Katherine Gallagher, who dreams of being kissed, and decides the only way this can happen is to become a star. She daydreams all the time, so she is moved to the special education class at St. Monica High School, the Catholic school she attends.A Catholic magazine is hosting a talent show — the Let's Fight Venereal Disease Talent Contest — at her school, and first prize is a role in a movie with good morals. Mary Katherine sees that her big chance is the talent show, and strives toward that. However, her grandmother will not let her enter the contest. Mary Catherine's competition is head cheerleader Evian, who is dancing with the jock Sky, the object of Mary Katherine's affections.When Grandma Gallagher finds out that Mary Katherine went behind her back and enrolled in the talent show anyway, she tells Mary Katherine the truth about how her parents died: They were stomped to death in an Irish step dancing competition.Despite this, Grandma Gallagher decides to help her win the talent show, and Sky's heart. However, another classmate, Slater, is after Mary Katherine's heart.
This movie provides examples of:
- Accidental Murder: How Mary Katherine's parents died.
- Bilingual Bonus: The story takes place in the town of Besamee ("Bésame" means "Kiss me" in Spanish).
- Black Comedy: Mostly the parts which refer to how Mary Katherine's parents died. Also when Slater mentions how his parents died.
- Bucket Booby-Trap: at the audition for the talent show. Filled with paint, not pigs' blood.
- Divine Intervention: Slater turns around when Jesus intervenes.
- Drugs Are Bad: Played with when Father calls role in class:Father: Thomas Smith?
Thomas: Here! But I don't know where here is man, 'cause I'm so wasted man!
Father: Thomas, it is a sin to even pretend that you-you-you're baked.
- Hippie Jesus - He doesn't look like a hippy per se, but the personality He uses to appear to Mary Katherine is definitely like a hippy.
- Hot God: Played with, as when Mary Katherine sees Jesus, He is a mixture of pictures she has seen of Jesus and important figures in her life, such as Skye.
- Kissing Warm Up: Mary Katherine makes out with a tree trunk.
- Meaningful Name: The name of the town (see Bilingual Bonus), in relation to Mary Katherine constant interest in being kissed.
- School Play: A talent show, but similar.
- Who Names Their Kid "Dude"?: Lampshaded when Mary Katherine fight with Evian, noting the fact that someone might be able to call his daughter as a brand of bottled water.