This drama tells the story of the female lead, Penny Franco, who agreed to a flash marriage with the male lead, Ethan Hartnett, to solve financial difficulties for her father's company. Ethan Hartnett was unhappy with the arranged marriage and left home, not seeing his wife, Penny Franco, for three years. They met again three years later and eventually fell in love.
By day, Cecilia is Marshall's meticulous personal secretary, flawlessly managing his life, but by night, she becomes his secret lover, pouring five years of her youth into a nameless relationship. Despite the company's whispers about her imminent rise as the 'boss's wife', Cecilia knows Marshall's heart still belongs to 'the one who got away', Jane. When Jane returns, Cecilia quietly packs her things, leaves a resignation letter, and gracefully exits. Reborn as a powerful investor, she reappears in Marshall's life, poised to rewrite their story.