Black Jack is a medical mercenary, selling his skills to the highest bidder. He is a shadowy figure, with a black cape, eerie black-and-white hair, and a scar across his face. Black Jack cures patients indiscriminately, from common folk, to presidents, to yakuza leaders, though he charges all of his patients absurdly high sums. This has given him a reputation for callousness and greed that he cultivates gleefully. In actuality, Black Jack possesses a complex personal code. He will cure a patient for free if they move him with the story of their suffering; however, he always establishes a patient's willingness to pay beforehand. If Black Jack cannot discover a redeeming story behind a patient, his charges stand. He will make exceptions in exigent circumstances, and may change his mind if proven incorrect in his assumptions. Black Jack gives much of the money he earns to charity, and considers it a favour when he takes the majority of a wealthy patient's money.
Opening
One of the best anime's EVAR! Created by the same person who did Astro Boy, Osamu Tezuka.
This anime is awesome, and suggest you check it out if you haven't already.
I'm currently rewatching this and it never loses it's replay. :D