Catching the eye of a wealthy gentleman, spunky Ha-won gets hired to live with his three immature grandsons so she can whip them into shape.

High school student Ha-won works hard at her jobs while being mistreated by her stepfamily. Impressed by her spirit, Hyun-min makes her an offer.

While posing as Hyun-min's fiancée, Ha-won encounters Ji-woon, who like Hyun-min is also a grandson of the Haneul Group chairman.

Ha-won comes to live with the chairman's three grandsons. Amid the odd circumstances, the chairman orders her to get everyone to dine together.

Yoon-sung tells Ha-won of the trauma the three grandsons have suffered. She presses on in her quest to bring them together.

Hye-ji recalls Ji-woon's promise to look after her, while Ha-won offers to help the chairman see his grandsons attend their fathers' memorial service.

The three cousins are moved by Ha-won and show up to pay their respects. Ha-won leaves the Haneul home and goes to stay with Hye-ji.

Hyun-min is humiliated after video of his confession spreads online. Ji-woon reveals the truth to Ha-won and brings her back home.

Ha-won is delighted at her success in bringing the boys on a trip together. Meanwhile, her stepmother searches for Ha-won's biological father.

Ha-won spies Yoon-sung heading into an organ transplantation center. Seo-woo's manager summons him to the office and shows him something.

Hye-ji's confession sends shock waves through both Ji-woon and Hyun-min. Ha-won hatches a plan to find out Ji-woon's true feelings.

The romantic tension heats up as Hye-ji comes to stay with the Haneul family. Ha-won works on drawing attention to herself.

Distraught by the appearance of a man claiming to be her father, Ha-won finds comfort in Ji-woon's arms. Seo-woo pours out his heart on the radio.

Ha-won faces a difficult choice when the chairman finds out about her and Ji-woon. Yoon-sung spies on the chairman's wife.

Blaming herself for the chairman's collapse, Ha-won disappears. Seo-woo and Hyun-min volunteer as potential liver donors.

Hwa-ja finally makes her power grab. The chairman's grandsons are united in their hope for his recovery, but the operation poses serious risk.

The transplant surgery is successful but Ji-woon remains unconscious. Hyun-min finds Ha-won and presents her with a pair of shoes.