Black Jack (TV) - episode 26 - 08 May, 2005

While hearing Pinoko talk about the abacus, Black Jack remembers when the teacher and father of Eiji, a boy, came to see him a long time before. Eiji dreamed of being an abacus champion, but he couldn't move his hands. Black Jack operated to fix them, but when his hands cramp up in a competition, reverts to using the abacus with his tongue. (Source: Wikipedia)