Biwamaru
Biwamaru (sometimes Biwa Maru) is a blind, itinerant acupuncture doctor, who wanders around Japan curing all sorts of ailments with miraculous speed. He is extremely disheveled in appearance, dressed in rags and walking with a twisted stick as a cane, and a rough bundle on his back. Biwamaru is effective, like Black Jack, an unlicensed doctor, since his practices are considered to be quackery by the medical establishment, while Biwamaru considers it barbaric to cut open a patient to cure them. This, as with Dr. Kiriko, Biwamaru is another nemesis who is too similar to Black Jack for the two to forgive their differences. Biwamaru also features in Tezuka’s best-known samurai manga, Dororo.
Notably, Biwamaru also appeared in Dororo as a blind musician and masters-swordsman. The crippled samurai Hyakkumaru, widely acknowledged as a prototype of Black Jack, encountered Biwamaru here and became his student in swordfighting, an interesting reversal of his role in Black Jack.