On Air is set in the background of the Korean SBC TV station. It mainly tells the stories between agents, popular artists, TV drama directors and famous screenwriters. It shows the stories that happened during the production of Korean dramas to the audience and reveals the world behind Korean dramas. The popular screenwriter Seo Young-jin (Song Yoon-ah) who has repeatedly created the myth of unbeaten ratings, the dark horse director Lee Kyung-min (Park Yong-ha) in the film and television industry, the most photogenic actress in contemporary Korea, Oh Seung-ah (Kim Ha-na), and the agent Jang Ki-jun (Lee Beom-soo) who has brought out a large number of stars. The four people came together to shoot a story about terminal illness that is neither a romantic Cinderella fairy tale nor a tear-jerking story - "Ticket to the Moon". Among them, Seo Young-jin has a flamboyant personality, and Oh Seung-ah is no less impressive. Lee Kyung-min is directing for the first time, and Jang Ki-jun is particularly humane to the actors. In addition to the four people, there are also many crew members. Under the system of Korean dramas being filmed and broadcasted at the same time, will the TV series they produce go smoothly? What kind of stories will happen in the meantime?