Hikari can be picked out of a crowd by the three, long spikes of hair shooting out of his head like beams of light.
Although he made a brief appearance in Astro Boy (1952-68) chapter “Shootout in the Alps”, Hikari went on to be the start of his own series, Hikari (1959). He also made an appearance in Black Jack (1973-83) among a few others.
(Source: Tezuka in English)