Gen Hoshino is a Japanese singer-songwriter, musician, actor, and writer.

"Gag" is a song by Japanese singer-songwriter and musician Gen Hoshino. It was released by Speedstar Records on May 8, 2013, as Hoshino's fifth single. A J-pop rock song with rock and roll composition, "Gag" was written by Hoshino for the film adaption of the manga Saint Young Men, starring Hoshino as the Buddha. The song was arranged by Seiji Kameda, marking Hoshino's only single to not be self-arranged.