Dr. Tenma is a Japanese brain surgeon working in Germany. He has it all: incredible medical skills, a great job, and a beautiful fiancée who also happens to be the daughter of the hospital's director. One day he is ordered to forgo operating on a critically injured man in favor of a more illustrious patient. Disillusioned by the hospital's politics, he decides from then on that he will do what he thinks is right, regardless of politics. Some time later, a young boy and his twin sister are brought in. The boy has a bullet in his head and requires an operation that Dr. Tenma knows only he is capable of performing successfully. Just as Dr. Tenma is about to begin the procedure, the mayor is rushed into the hospital and the director instructs Dr. Tenma to leave the boy to operate on the critically ill mayor. Dr. Tenma decides that he will do what is right and go ahead with the boy's operation. The young boy's operation ends in success but the surgeons operating on the politician fail. As a result, Dr. Tenma is passed over for a promotion and his fiancée calls off their engagement. Soon after this incident, strange murders begin to occur, all of which benefit Dr. Tenma greatly. As a result, he becomes the prime suspect although the police have no evidence against him. It seems that the boy whose life he saved is heavily involved in it somehow and that there is much more to him than meets the eye.