If there is a single founder of manga and Japanese anime as they exist today, that person is Osamu Tezuka; and nobody would disagree with me. You might have heard of some of his works, such as Astroboy or Kimba the White Lion, which were shown in the USA some time ago. But being the creator of the first animated series in Japan isn't all of his accomplishments. His works on anime might be limited, but often, his manga are deeper and more insightful of the human psyche than any of the cheap bestsellers that are printed today. He took on themes like the life of Buddha, immortality and reincarnation in the Phoenix series, and the irony of life and death in Black Jack.
And he was also an MD - but he inevitably chose to devote most of his career writing hundreds of pages of manga every month until his death in 1989. In a way, Black Jack may be his alternate ego.
Black Jack is a genius with the scalpel - he undertakes numerous impossible surgeries; however, he doesn't have a license to practice. He is both ostracized and revered at the same time by the medical community for this reason. His brooding personality and the scars are due to an accident that killed his mother and literally blew him apart as a child. He knows firsthand the suffering that many of his patients go through. Why then does he charge outrageous amounts of money (whereas sometimes he only charges "a dollar" on a whim)? We never see him spending any of it, and he lives in a small shack with Pinoko, a girl whose life he virtually "created." In a setting where happy endings don't always happen, that might be the least of your frustrations; but his stories, far from being simple soap operas, transcend the genre of manga altogether.