Lance Locke, pressured to marry, uses a rent-a-girlfriend app. He opens a portal, saving Empress Celeste Jiang, betrayed by Finn Shaw, now powerless. They form a rental contract. With Supreme Nine Swords, Lance gains abilities. They confront the Locke Family and assassins. Lance discovers his past: Aethelgard's Supreme, protecting Celeste Jiang. He traverses worlds, slays Finn Shaw, and pacifies turmoil. Their rental agreement evolves; he and Celeste Jiang wed, staying together across realms.