The manga Kyojin no Hoshi, Star of the Giants, ran in Weekly Shōnen Magazine from 1966 to 1971. One device from the story became famous: the dai rīgu bōru yōsei gipusu, the major league ball training cast, which the hero wears all the time to build his muscles. The magazine Hiragana Times calls the series a pioneer of supokon, sports and guts, manga.