Japanese title: こちら秘封探偵事務所
Illustrations from a web serialization by fanfic writer Asagihara_Shinobu_(Rhythm_Five) involving Usami Renko and Maribel Hearn in Gensokyo.
Serialization in Japanese at http://longnovel.com/touhou001/
Chapter 1Chapter 2Chapter 3Chapter 4Chapter 5Chapter 6Chapter 7Chapter 8Chapter 9Chapter 10Chapter 11Chapter 12Chapter 13Chapter 14