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.
Yoon Jong-Woo is a man in his 20's. He has lived in a small town for all of his life, but he gets a job at a small office in Seoul. Yoon Jong-Woo moves out to Seoul and stays at a cheap apartment which shares its kitchen and bathroom with other residents. He doesn't like staying at the apartment and he doesn't like the other residents who seem weird and suspicious.
An explosion at the National Assembly kills everyone in the cabinet, leaving Park Mu-jin, the Minister of Environment, to become the next president. Park Mu-jin is a scientist-turned-politician who has no ambitions in politics, but as the acting president for 60 days, he is compelled to investigate the truth behind the attack. Based on the popular American series Designated Survivor.
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.
“We are neither kids nor adults. When do we become adults then?” Min Jae and Seo Yeon are no different from ordinary 17-year-old high school students. Min Jae is silent and sensitive, yet a good student. Seo Yeon who plays the piano wished to enter an arts high school but failed. As they grow into adults, their surroundings and the reality they face get harsher. These two somehow similar but different friends get closer as they overcome their growing pains together.
Jenny Jang (Kim Sun-A) is poor and works at bathhouse in Gangnam, Seoul. She starts a new job as a housemaid for a conglomerate family. She becomes successful and then runs J Boutique. She also begins work as a lobbyist. Jenny Jang gets involved in an international city development project.
People think it is a doctor’s bounden duty to save a patient’s life. But things are different now. Things are needed to be considered other than saving one’s life. Modern medicine has been developed remarkably, and it is quite possible to save a person's life who is on the verge of death. But we need to think about if prolonging a patient’s life makes the patient truly happy. Cha Yo Han is a promising doctor who needs only 10 seconds to figure out a patient’s condition. While he is gaining his fame with his outstanding skills, he confronts one patient who changes his whole life. Kang Si Young is a doctor with a warm heart. Her family has been doctors for generations. She takes after her mother’s exceptional talent and her father’s high empathic ability. But one day, she suddenly leaves the hospital. After a year later, she goes to the penitentiary to serve as a temporary medical doctor, and she meets a prisoner who was a former doctor. He is a genius who can grasp the patient’s condition within 10 seconds. After meeting him, Si Young’s life totally changes. And the day she comes back to the hospital, she meets the prisoner again, and this time, he is a professor. Doctor John is a human medical drama of anesthetists who seek the cause of mysterious pain their patients suffer, like detectives chasing after a suspect.