Park Shi-On (Joo Won), is an autistic savant who has the mentality of a ten-year old. As a child, he was sent to a specialized care centre, where he discovered genius capacities for his autism. Coupled with an exceptional memory and keen spatial skills, he eventually entered pediatric surgery. He has 6 months to prove himself capable. However, his mental and emotional development seems to have stopped at 10-years-old, which makes for incredible conflicts in and out of the O.R., especially with the hotheaded surgeon Kim Do Han (Joo Sang Wook). He was labelled as a soulless robotic doctor that relied heavily on his photogenic memory only and not feel what the patient needs. Despite warm-hearted and fair colleagues like Cha Yoon Seo (Moon Chae Won) and Han Jin Wook (Kim Young Kwang), it’s a fierce and competitive adult world. He faces another challenge during his residency – he fell in love with Yoon Seo.