High School DxD Novel Volume 5 was written by Ichiei Ishibumi and features illustrations by Miyama-Zero.

Ah, summer. The season to bask in the beauty of swimsuits at the pool or the beach. At least, that’s what Issei’s hoping for when he tags along with Rias on her trip home to the underworld. However, what awaits him isn’t half-naked babes, but a hellish training regimen concocted by Azazel, the fallen angel teacher!