体育館裏のホーリー

From Author Wars - https://authorwars.com/books/ti-yu-guan-li-nohori-3034103.html

Overview:

Title: 体育館裏のホーリー
Author: 石踏一榮
Year: 2010
Type: Novels
Series: ハイスクールD×D / High School DxD
Number in Series: 6

Variant Titles:

2022. Holy Behind the Gymnasium