The songstrell Ruberiot is ordered to write a song about Star for the tradition of Song Day, but Star is reluctant to participate because it portrays princesses as being perfect. Ruberiot ultimately convinces her to let him write a song about the real her, but inadvertently reveals to the people of Mewni that Star lost the book of spells, and that she has a crush on Marco.
After having skirmished with a number of dangerous monsters, Star Butterfly arrives on Earth to live with the Diaz family. However, rather than living a normal life, Star continues on having to battle villains both throughout the universe and in their high school, although if only to protect her extremely powerful wand, an object which she is still confused with.