High School DxD, Vol. 10 (light novel)

The Rating Game with Sairaorg is days away, and the Gremory Familia is training hard to get ready while preparing for the Academy Festival. However, trouble strikes when Rias suddenly becomes upset with Issei, leaving the hapless bonehead bewildered about how to fix things. He's not even sure why the prez is angry. Okay, he has one idea, but it's got to be too far-fetched...right? Mending the pair's relationship and defeating Sairaorg may require Issei to overcome his greatest challenge-and his deepest trauma!