Kojirou Sasaki

Based on the real-life Japanese master swordsman, from whom he gets his name, the primary characteristics which distinguish Kojiro Sasaki are his energy, his quick temper, and the skill and constancy with which he handles a (usually bamboo) sword.

Although his first appearance was in Benkei (1954), his break-out (and namesake) role was in Oh! We Three (1956).

He puts a sense of fun into a scene in which he appears, including (or particularly) when the sword is conspicuously out-of-place. In addition to many roles in Black Jack (1973-83), he has appeared in The Crater (1969-70), Rainbow Parakeet (1981-82), and Lion Books (1971-73) a few times each, plus many appearances in other, lesser-known, Tezuka manga series.

He also appears in anime TV Special, The Undersea Super-train: Marine Express (1979), which is an excellent example of his seeming incongruous as a classic Japanese swordsman in a futuristic setting.

(Source: Tezuka In English)