Oh Je Ro is a musical genius who had always dreamt of learning the piano, but had to work in a piano factory as tuner instead of going to school in order to support his sick father. He had despaired of ever being given a chance to learn and thought the name his father gave him sounded like "Oh, Zero", signifying his lack of hope in the future. This changes when he meets an elementary school teacher, Yoon In Sa, and begins a delicate love story with her.

Secret Investigation Record is based on cases detailed in the Annals of Joseon History with a bizarre twist; these incidents incorporate mysterious, supernatural elements that cannot be explained through science. Kim Hyung Do is an inspector of the state whose single-minded focus on his investigations into administrative misdeeds bring him into direct contact with these strange mysteries. Heo Yoon Yi is a government employee who aids him and attempts to understand these scientific impossibilities with an open mind, in contrast to his cynicism.

With Jung Bo-Seok playing an irresponsible, selfish prick of a father leaving his family to save his bacon during the Korean War, and super-talented Shim Eun-Kyung playing his daughter Jo Gyeongsuk, this 4 episode special mixes very dark and wicked comedy with tragedy in such a breezy, eclectic way that you wonder if you're really watching a Korean TV Drama, particularly considering how polished all this looks. Family love during the Korean War has never been this intelligent. Nor this funny.