Ha Jung (Han Hyo Joo), a first-year college student, is interested in a boy named Su Wook (Lee Young Hoon) who works at a secondhand bookstore near her school. In order to see Su Wook, Ha Jung visits the shop to buy and sell books; over time, her lifestyle becomes focused on Su Wook. She learns that he rides around on his bicycle, and this leads her to learn to ride one. They begin to express their feelings for each other, but neither of them are aware of each other's painful secrets from the past.