Star is feeling down when her crush Oskar has no calls from her, so Marco tries to cheer her up only that he accidentally summons Ludo and his army of monsters.

Star goes through mewberty, which covers her body in purple hearts and sets her off onto all the boys in school.

Star accepts her ex-boyfriend Tom's invitation to Demon Prom, but Marco is suspicious of Tom's intentions.

Star rebels after the school guidance counselor, Mr. Candle, insists that her future is set in stone.

When Marco teaches Star how to ride a bike but forgets to tell her about brakes, he teams up with Oskar and Glossaryck to save her.

When Star is nominated as Mayor of Detention, she must help her constituents with their various problems.

Hoping to help her forget about her strained friendship with Marco, Star's friends convince her to ditch the Diaz' end-of-the-school-year party for a more dangerous bash.

Marco is determined to consume 50 tacos in order to win a special prize that is being offered at Britta's Tacos restaurant.

Star and Marco need Janna's help to return to Mewni.

Star, Marco, Janna and Tom lose their memories as they traverse amnesia-inducing waters to get back to Mewni.

Star and Marco face their final conflict.