Black Jack the Movie

Both are about men in the medical fields. 

While the plots of the two movies are quite different, they have many similarities. Both anime are directed by Osamu Dezaki, so their overall directing style and mood is quite similar. Also, the art and animation are quite similar as well. Apart from the style, the main characters, Duke Togo and Kuroo Hazama are also very similar. They are both professionals who operate in the underground world, and can be hired for a certain fee. While Duke Togo is a professional assassin whose job is to take lives, Kuroo Hazama is an unlicensed doctor whose job is to save lives, making the two characters two sides of the same coin. Also, they are both portrayed as cool, mysterious and badass characters. read more 

Both have a dark mysterious side to them