Education:
- 1987: Waseda University School of Economics & Political Science
- Tokyo Metropolitan Musashi Senior High School
Pennames:
- Agi Tadashi, shared with his older sister, Yuko Kibayashi (樹林ゆう子), non-fiction writer.
- Seimaru Amagi (_天樹征丸_)
- Yuma Ando (_安童夕馬_)
- Yuya Aoki (_青樹佑夜_)
- Joji Arimori (_有森丈時_)
- Hiroaki Igano (_伊賀大晃_)
- Ryo Ryumon (_龍門諒_)
- S.K.
Received the Kodansha Manga Award for Shounen in 1995 (The Kindaichi Case Files) and in 2003 (Kunimitsu no Matsuri).
