Monthly Shōnen Sunday (Japanese: 月刊少年サンデー, Hepburn: Gekkan Shōnen Sandē), alternately known as Gessan (ゲッサン) (a portmanteau of "Gekkan" and "Sandē" from its full Japanese title), is a monthly shōnen manga magazine published in Japan by Shogakukan since May 12, 2009 (the June 2009 issue).

[3] The magazine was announced in February 2009,[4] with Hayashi Masato, at that time editor of Weekly Shōnen Sunday, editing the monthly magazine as well.

[5] Manga artists who debuted new series or stories in the magazine include Yellow Tanabe, Mitsuru Adachi, and Kiyohiko Azuma.

[6] There are 25 manga series being serialized in Monthly Shōnen Sunday.