Stand-In Bride Spoiled Crazy by Underworld Tycoon

Impoverished Lynn agrees to impersonate the white moonlight fiancée of mafia tycoon Ethan and sign a substitute bride contract to save her gravely ill mother. Ethan sets strict no-love rules, but her quiet strength makes him break every boundary. When the real white moonlight Claire returns, Lynn leaves heartbroken. Ethan puts aside all pride to chase her across the city, and the final truth emerges: she was always the one he's loved for years.