Note: for the purposes of this article, all Japanese names are presented in the Western fashion, with the given name followed by the family name.
There's a Kurt Vonnegut story called "Who Am I This Time?" about a quiet and formless small-town man named Harry Nash who comes to life only during productions at the local theater, in which he becomes entirely consumed by whatever character he's playing. A tabula rosa defined only by his current role, Nash is a complete mystery beyond his otherworldly talent. This story springs to mind almost every time I watch one of Takashi Shimura's rapturously immersive performances - he's perhaps the most accomplished actor in film history to have a mere stub for a Wikipedia page.
When people think of actors closely associated with the films of Akira Kurosawa, Toshiro Mifune is rather understandably the first person to come to mind. Mifune's raw, ribald, and irrepressible energy brought some of cinema's most gloriously scripted characters to ferocious life, and the 16 films he made with Kurosawa famously amount to one of filmdom's most mutually beneficial partnerships. Mifune was Kurosawa's roaring muse, and their fiery relationship is the stuff of legend (Stuart Galbraith IV's The Emperor and the Wolf is an invaluable tome on the subject - Mifune is the "Wolf"). But it's often ignored that of those 16 films Takashi Shimura was in all but one (1957's The Lower Depths) - if Mifune was the muscle, brawn, and guts of those films, Takashi Shimura was their heart.