Astro Boy, created by Osamu Tezuka in 1963, is considered the first modern anime and helped to popularize the genre both in Japan and around the world.

The Kamakura period, which lasted from the 12th to the 14th century, was a time of political upheaval and marked the rise of the shogunate.

The Showa period, which lasted from 1926 to 1989, was marked by Japan's militarism and involvement in World War II.