Ditto is a 2000 South Korean science-fiction romance film directed by Kim Jeong-gwon. The plot of the film is similar to that of another movie released in 2000, Frequency, in that two people separated in time are somehow able to talk to each other using amateur radio. The film begins with Yoon So-eun (Kim Ha-neul), a student at Silla University eagerly awaiting a certain student Dong-hee (Park Yong-woo) returning to school after serving in the army. She meets him outside the amateur radio club room, where she tells him HAM radio is her hobby, and he thanks her for all the letters she wrote him during the war. Visiting her friend Sunmi-Hur who is recuperating from a broken leg in the hospital, So-eun tells her she is in love with Dong-hee.