CoroCoro Comic is a monthly children’s magazine by Shogakugan, which began publishing in 1977. Originally conceived as a place to house old chapters of Doraemon, the magazine soon became home to a host of manga for the Kodomomuke crowd and hasn’t stopped ever since.. The magazine is aimed at younger boys than shounen books typically aim for, so their manga usually follows their interests.

: https://tvtropes.org/pmwiki/pmwiki.php/Magazine/CoroCoroComic