Young-Mi (Ha Ji-won) was brought up in a loving environment. Her parents taught her to meet the world with a smile on her face, and not be deterred by bumps in the road on her way through life. They also taught her that somewhere out in the world she would meet her one true love. But alas this felicity was not meant to last. Young-Mi’s parents die, and leave her alone at a young age, and suddenly she’s forced to grow up very quickly.

However Young-Mi is well prepared. She ventures into the world with an appetite for life, and many dreams and hopes for the future. She goes to school and studies hard, and one day a package arrives for her. A beautiful pair of shoes. There’s no sender on the package, and when she attempts to track the origin of this gift the trail ends at a P.O. box. Later when she enrolls in college and attempts to pay her tuition she finds that it’s just been paid. Someone out there is watching out for her. But who? And why?

After a while she gives up, trying to track down this mysterious benefactor, and instead she figures that the best way to thank him would be to work hard and better herself.

When she’s completed her education, Young-Mi lands a job at a radio station, as a staff writer on a popular show. As luck would have it, there’s an apartment available close to the station. It belongs to a co-worker currently on sick leave. Young-Mi moves into this new place, and she also gets a roommate, one of her colleagues. When her laptop computer breaks down she turns on the desktop belonging to the owner of the apartment. Then she notices that an e-mail has just arrived, and she reads it. The mail was sent by the woman who used to live here, addressed to herself. In the mail she explains that a serious virus is slowly destroying her mind, and she fears she’ll soon lose all memory of who she is and what she’s done. She reveals that she’s spent most of her adult life longing for a guy, who doesn’t even know she exists.

Through the e-mails Young-Mi begins to follow the story of this girl and this boy. Meanwhile she also begins to notice a guy who works in the station’s library. And still, every now and then, a package arrives from her secret benefactor…