Bangai is a collection of short extra stories related to the author's other works. The first volume includes an erotic manga featuring characters from the BL manga "Banchou Monogatari" and a gag manga from the BL manga "Haiboku Eiyuu, Katajikena". The second volume contains a serious and erotic side story to the BL gag manga series "Banchou Monogatari", set after its first three volumes.