Mio, daughter of the nearly bankrupt Ogasawara Trading Company president, works tirelessly to save her father’s failing business. One day, when a shady man tries to swindle her, she’s rescued by Kaisei Saionji, the heir to the mighty Saionji Zaibatsu. Learning of her plight, he offers a deal: 'You have three options.' Among his proposals, Mio chooses... a contractual marriage into the Saionji family. Determined to save her family, she resigns herself to a loveless union, only to find herself increasingly flustered by her unexpectedly sweet husband…!