Characters Kang Hoon
Kang Hoon: A member of the 1st class of the Child Doctor Training Project, called a 'perfect son' by those around him for his handsome looks and meticulous skills. Due to his prickly personality, he is nicknamed 'ER Siberia.' He is a 3rd-year fellow in Emergency Medicine. Male.
Jang Hada
Jang Hada: A member of the 1st class of the Child Doctor Training Project who treats everyone with a warm heart and kind nature. Known as the 'ER Vitamin' for her warm personality. She is a 3rd-year fellow in Critical Care Medicine. Female.
Gu Haejo
Gu Haejo: A member of the 3rd class of the Child Doctor Training Project with a positive and lively personality, always the first to hear the siren. Her nickname is 'ER Rabbit.' She is a 1st-year fellow in Neurosurgery. Female.
Gong Juin
Gong Juin: Once called the 'ER Princess' for her flashy appearance and bold behavior, she now acts as the 'ER Blank Cartridge,' maintaining discipline in the ER in place of Chief Gu Haejo. Female.
Cheon Jaesu
Cheon Jaesu: Famous for being a genius since childhood. After working as a genius surgeon in the US, he joined the 'Regional Trauma Center' at Dasarang Children's General Hospital, which handles severe trauma patients separately. His excessive confidence earned him the nickname 'ER Jerk.' He is a member of the 3rd class of the Child Doctor Training Project and a 3rd-year fellow in Trauma Surgery. Male.
Lee Roun
Lee Roun: A gaming geek who appears like lightning when an emergency call comes, even in the middle of a game. Due to this, he is called 'ER Hong Gil-dong.' He is a member of the 2nd class of the Child Doctor Training Project and a 2nd-year fellow in Orthopedic Surgery.
Na Seona
Na Seonwoo: A member of the 2nd class of the Child Doctor Training Project who is always full of confidence and loves to step forward. Because of this, he is called 'ER Captain Na.' A 2nd-year fellow in Thoracic Surgery, he is the son of the owner of Jeil Hospital and worked there before joining Dasarang Children's General Hospital.
