The Canary Who Became the Cure

Foster girl Ivy signs a contract to sleep beside insomniac heir Ethan, only to learn she's a stand-in for his first love Chloe. When the contract ends, she leaves for London. Ethan's illness worsens; he discovers Ivy—not Chloe—saved him from a childhood fire. He chases her, wins her back, and they marry after healing together.