Ōishi has performed theme songs for Overlord (all three seasons), Hand Shakers, Ace of Diamond, Ace of Diamond: Second Season, Prince of Stride: Alternative, and SSSS.
As a solo artist he has performed theme songs for Monthly Girls’ Nozaki-kun, Tada Never Falls in Love, and Cop Craft.
Currently, Ōishi is still scheduled to continue with his solo live performance at Line Cube Shibuya in Tokyo on May 21.
He also composed and arranged theme songs for Makura no Danshi and A3!