Princess Star Butterfly falls in love with Marco Diaz.
Unable to confess, she is gifted by a deus ex machina with her best friend's phone number. Never minding the strange area code, she immediately calls him, and is overjoyed to find out that he has a crush on her as well.
But, the next day, when Star recounts the previous day's confessions to Marco, he only looks at her with a perplexed expression. After some investigation, she finds out that the boy she called is not the same boy she fell in love with. In fact, Diaz doesn't exist in this universe at all. The other Marco is the alternate universe counterpart of her crush, who has fallen in love with her AU self, who too is blissfully unaware of his crush.
Hijinks ensue as they strike up a deal to give each other their darkest, most private secrets in order to equip each other with the weapons they need to conquer the heart of their other selves. While the two chase their respective loved ones, DRAMA ensues as they begin to fall in love with each other instead and question the NATURE of LOVE.