正体不明なんですけど。
From Author Wars - https://authorwars.com/publications/zheng-ti-bu-ming-nandesukedo-551820.html
Overview:
- Title: 正体不明なんですけど。
- Author: 榊一郎
- Year: 2005
- ISBN-10: 4757725086
- Publisher: エンターブレイン
- Pages: 277
- Binding: Paperback
- Type: Novel
- Title Reference: 正体不明なんですけど。
- Notes: Data from Amazon.co.jp
Cover artist per cover credit
Title transliterates as "Shoutaifumei Nandesukedo." (Actually, I'm Sure It's Unidentifiable.)