Shazelle Lozano believes in the Red String Theory - the belief that those destined for each other are bound by an unbreakable, invisible thread. But when her parents split, that belief shatters. Crying alone at the park, she meets Zaedan - another kid whose world was broken by the exact same heartbreak. Unlike Shazelle, he doesn't believe in destiny. He believes that: "We choose who we end up with." Refusing to let go of her last shred of hope, she insists that their meeting isn't a coincidence - they are destined to be soulmates in the form of friendship. Too young to have social media, with no names to search and no numbers to call, they part ways with a single promise: to find each other again someday. But promises are easily made and hard to keep. Years will pass. People will change. In a world this big, can a promise and an invisible string be enough to pull them back together?