Cause of death: stomach cancer
Osamu Tezuka (手塚 治虫, born 手塚 治, Tezuka Osamu, (1928-11-03)3 November 1928 – 9 February 1989) was a Japanese manga artist, cartoonist and animator. Born in Osaka Prefecture, his prolific output, pioneering techniques and innovative redefinitions of genres earned him such titles as "the Father of Manga" (マンガの父, Manga no Chichi), "the Godfather of Manga" (マンガの教父, Manga no Kyōfu) and "the god of Manga" (マンガの神様, Manga no Kami-sama). Additionally, he is often considered the Japanese equivalent to Walt Disney, who served as a major inspiration during Tezuka's formative years. Though this phrase praises the quality of his early manga works for children and animations, it also blurs the significant influence of his later, more literary, gekiga works.
Tezuka began what was known as the manga revolution in Japan with his New Treasure Island published in 1947. His output would spawn some of the most influential, successful and well-received manga series including the children's mangas Astro Boy, Princess Knight and Kimba the White Lion, and the adult-oriented series Black Jack, Phoenix and Buddha, all of which won several awards.
Tezuka died of stomach cancer in 1989. His death had an immediate impact on the Japanese public and other cartoonists. A museum was constructed in Takarazuka dedicated to his memory and life works, and Tezuka received many posthumous awards. Several animations were in production at the time of his death along with the final chapters of Phoenix, which were never released.
Source : Wikipedia