There used to be a legendary surgeon in Japan who simply went by the name K. His speed, accuracy and overall brilliantness were second to none and he helped a countless number of patients. However, five years ago, he disappeared, never to be heard from again.

Now, a man who looks identical to the original K has appeared, claiming he is a descendant from a long line of shadow doctors that have been working behind the scenes. This new K is just as talented as the original one and has chosen to continue the work left by the old K. He has vowed as a doctor to uphold the importance of human life.