Tadashi Agi (亜樹 直 Agi Tadashi) is a Japanese manga storywriter, novelist and screenwriter. His original name is Shin Kibayashi (樹林 伸 Kibayashi Shin). He was born in 1962 in Tokyo, and graduated from Tokyo Metropolitan Musashi Senior High School and Waseda University School of Economics & Political Science. The penname "Tadashi Agi" is shared with his sister. Under the name Yuma Ando, he received the 2003 Kodansha Manga Award for shōnen for writing Kunimitsu no Matsuri.