User blog comment:SpookyBoogie27/Light Novel Spoilers/@comment-33447191-20130325064138/@comment-33447191-20130521141840

I'm sorry, I don't know; you'd probably have to purchase the Fantasia Bunko 25th Anniversary Book. However, there is a site that translates it in Chinese - http://book.sfacg.com/Novel/12225/55255/376464/.

Actually n0m@n is actually in the process of translating that particular short story and is 83% of the way completed - http://www.baka-tsuki.org/project/index.php?title=High_School_DxD:Rias_in_Wonderland.

I hope that will suffice, if not, I'm sorry I couldn't be of more help.