The Mighty Atom Club magazine was launched after the grand success of the 1963 anime, "Mighty Atom" (Astro Boy). It was a part of the official fan club: "Mushi Productions Tomo no Kai (Friends Association)". It disbanded after Mighty Atom's initial airing on TV in late 1966.

Based on Tezuka Osamu's manga series "Jungle Emperor" from 1950, one-shots started to appear in the magazine in March of 1966 (Vol. 20-28). Drawn by Tezuka's associates, these eight stories would later air as episodes from the first and second anime series.

The Jungle Emperor chapters were never re-printed and stay exclusive to the original magazines.