Lee Kang-hoon, who graduated from the top medical school, works at the top hospital and is the top neurosurgeon around. Basically, he's Brain No. 1. (And he works on brains, too!) He has ambitions to become the director at his university hospital. He is obsessed with success, which is probably both his greatest flaw and strength, since it makes him steely and fierce. However, once he meets his sunbae Kim Sang-chul, the prickly genius doctor and world-famous neurologist, he turns over a new leaf and becomes a sincere doctor. Seo Joon-suk is a doctor and will become Lee Kang-hoon's rival. Yoon Ji-hye is also a neurosurgeon who grew up in an ordinary family. She is extremely strict in matters of work and study, but has a warm bedside manner with her patients