High School DxD Novel Volume 10 was written by Ichiei Ishibumi and features illustrations by Miyama-Zero.

With the school festival just around the corner, the members of the Occult Research Club have their hands full preparing. And if that wasn’t enough, their Rating Game with Sairaorg is fast approaching, too! Unfortunately, Rias and Issei have an argument that drives a wedge between the pair. Can they mend their relationship in time for the biggest fight of their lives? And will they even stand a chance against the impossibly powerful Sairaorg if they do?