To save her critically ill grandmother, who is hospitalized, Su Wanxing is forced to take the place of her cousin Su Manni, who has run away from her wedding, and marry Lu Yanzhi, the mysterious, aloof president of the Lu Group, whom she has never met. They sign a three-year premarital agreement for the substitute marriage. What should have been a transactional marriage in which each gets what they need, with an agreement not to interfere in each other's private lives, takes an unexpected turn. Before and after they register their marriage, Lu Yanzhi goes against the terms of their agreement, obsessively researching breakfasts that are gentle on her stomach and quietly paying her medical bills, hiding his concern in awkward acts of kindness.
Living under the same roof, the two set up rules like roommates sharing a rental, yet gradually grow closer through breakfast together each morning, the warmth of late-night cooking in the kitchen, and countless small moments of mutual care. Su Wanxing must thwart the Su family's schemes and her cousin Su Manni's malicious attempts to undermine her, while protecting her gravely ill grandmother. Lu Yanzhi is burdened by an old physical ailment and conflicts within his family. Their marriage contract, once a cold arrangement of mutual interests, gradually gives rise to feelings that are restrained yet tender. Amid the thorns of reality, the two slowly make their way toward each other.
