Masuda Kōsuke Gekijō: Gag Manga Biyori (Japanese: 増田こうすけ劇場 ギャグマンガ日和, Hepburn: Masuda Kōsuke Gekijō Gyagu Manga Biyori, "Kosuke Masuda Theater: Good Day for Gag Manga"), or simply known as Gag Manga Biyori, is a Japanese manga series written and illustrated by Kosuke Masuda. It started in Shueisha's shōnen manga magazine Monthly Shōnen Jump in the January 2000 issue. The magazine ceased publication in June 2007, and the series was transferred to the then-brand new magazine Jump Square in November of the same year, where it was published until November 2014. Shueisha collected its chapters in fifteen tankōbon volumes. The manga continued in Jump Square, under the title Gag Manga Biyori GB, in December 2014. Gag Manga Biyori features a hyperactive, random, and nonsensical style that revolves