The Demon King decrees that his four heirs must find and marry the last descendant of the legendary Demon Slayers to claim the throne. These four handsome heirs arrive at a human school with their own dark motives. Meanwhile, in a desperate attempt to retrieve her mother's sacred bracelet, a young woman accidentally offends one of the heirs and finds herself burdened with a massive debt. Forced to become their personal maid, she discovers a terrifying secret: they are not all human! Thus begins a high-stakes adventure of magic, debt, and forbidden passion. Caught between five powerful beings, she must find her own strength to survive the demon realm. A sweet and funny story of hidden identities and fated hearts. Success is her only protection.