Wie Dae-Han (Song Seung-Heon) is an ex-lawmaker and is a materialistic kind of politician. He wants to get elected as lawmaker again. One day, 18-year-old girl Da-Jung (Roh Jeong-Eui) comes to him. She tells him that he is her real father. Her mother raised four children, including Da-Jung, alone, but she died in a hit-and-run accident. Da-Jung is the only one now taking care of her 3 younger siblings. Wie Dae-Han accepts Da-Jung and her 3 younger siblings. He carries out “The Great Show” to become a lawmaker again.
Music producer and composer Ha Rib made a contract with the devil to trade his soul for fame. This devilish transaction brought him all the fame he could ask for, producing many hit songs. As the contract expiration draws near, he bargains with the devil for an extension. For that, he must find another person to sell the soul. Ha Rib finds a perfect candidate, but contemplates because she would have to suffer for 10 years for his selfish fame.
In modern society, there are people who are neglected and suffering. They are often involved in unfortunate events, such as industrial accidents, and end up dying. Most of the disasters could be prevented in advance with little attention. However, some companies or public organizations tend not to prepare for potential accidents because of the high cost. That’s how industrial accidents take place. Doctor Detective is a drama where medical doctors treat the patients suffering from industrial accidents and look into the truth behind the accidents. The story of the drama starts when Joong Eun, who is an enormously talented medical doctor, gets to join an undiagnosed disease center(UDC) in the middle of experiencing difficulties in her personal life. And she starts to look into her patients' diseases caused by industrial accidents and work on revealing the truth concealed by those with power.
Lee Jae-Sang (Rain) is a lawyer at JK Law Firm, which is one of the biggest law firms in South Korea. He is an excellent lawyer, but he only cares about winning for his benefit. One day, he has a mysterious car accident and he is drawn into a parallel world. There, Lee Jae-Sang finds himself working as a prosecutor. He is strict in carrying out the law. He is married to Ra Shi-On (Lim Ji-Yeon), who loves Lee Jae-Sang and is faithful to him. In the world where Lee Jae-Sang came from, he broke up with Ra Shi-On ten years earlier and Ra Shi-On works as a detective. Lee Jae-Sang struggles to cope with his different selves.
Cellphone app Joalarm is created. If someone likes you and they are within 10 meters of you, the alarm for the app rings. The app also shows how many people like you, but the app doesn't reveal specific details on who likes you.
Kim Jo-Jo (Kim So-Hyun) is a high school student. She is pretty and smart. She seems like cheerful person, but her parents died when she was young. Since the death of her parents, Kim Jo-Jo has lived with aunt's family. Living there is not easy for Kim Jo-Jo. She doesn't download the app Joalarm.
Meanwhile, Hwang Sun-O is a popular male student at the same high school where Kim Jo-Jo attends. He is the son of a wealthy family, but he is not loved by his parents. His best friend Lee Hye-Young also attends the same high school. Hwang Sun-O notices that his best friend Lee Hye-Young likes Kim Jo-Jo. Hwang Sun-O wants to know if his friend really likes her, so he kisses her.