Yeong-ju is a girl with cute looks, an innocent smile, and a brilliant talker. She is also in prison for fraud. She easily convinces the evaluation board to grant her parole in time to attend her older sister's wedding. As soon as she's released, she boards a train for Busan with the wooden ducks she'd handcrafted as her wedding gift. On the train, she sits across village pharmacist Hee-cheol, who is on his way to propose to his girlfriend with his deceased mother's family heirloom ring. Yeong-ju witnesses a pickpocket stealing the ring from Hee-cheol, and afraid of becoming the suspect and violating her parole, she steals the ring back for Hee-cheol. But in the process, she is unable to board the train on time, missing it and leaving her wedding gift bag on the train.

Determined to find her bag, she tracks down Hee-cheol, and arrives in his hometown Yonggang Village. But the situation becomes complicated when his family members mistake her as their future daughter-in-law due to the ring, welcoming her to the family. Unwilling to tell them the truth so that she can find her bag then leave, Yeong-ju sweetly plays along, even telling them that Hee-cheol is the father of her unborn child. Meanwhile, Hee-cheol, who wasn't able to make the marriage proposal because of the lost ring, comes back home with a heavy heart. He is enraged to find himself in the middle of Yeong-ju's schemes. Worst of all, no one believes him, thinking he had abandoned his poor pregnant fiancee, and he ends up miserably kicked out of the family home.

As a showdown brews between Yeong-ju and Hee-cheol, pitting truth vs. lies, they gradually get to know each other and fall in love.