AnnaJo (Han Ye-seul) is a rude, spoiled, arrogant and impossible-to-please American-bred heiress. She returns to Korea only to continue being a controlling wife to her already cowardly husband, Billy Park (Kim Sung-min). When her yacht gets stuck for repairs, she hires local handyman Jang Chul-soo (Oh Ji-ho) to fix her shower, but when they have aheated spat over her dissatisfaction with his work and refusal to pay, she pushes him overboard and dunks his tools into the ocean right along with him. Later, after a quarrel with Billy that threatens to end their marriage, she herself gets drunkenly pitched overboard and falls victim to a bad case of amnesia.
In the hospital, she ends up beside none other than Chul-soo, who's still recovering from hisown swim in the ocean for his lost tools. Unknown to her, he's been raising his three orphaned nephews in their unkempt house and desperately needs a nanny. Taking advantage of her memory loss, he manages to convince her that she's his live-in girlfriend and renames her Na Sang-shil. But he didn't expect her spoiled selfishness to slowlyturn into compassion. And he didn't expect to fall overboard again — this time, for her.