放課後のラグナロク

From Author Wars - https://authorwars.com/books/fang-ke-hou-noragunaroku-3035572.html

Overview:

Title: 放課後のラグナロク
Author: 石踏一榮
Year: 2010
Type: Novels
Series: ハイスクールD×D / High School DxD
Number in Series: 7

Variant Titles:

2022. Ragnarok After School