The voice cast for KJ File includes: Motomu Kiyokawa, Issei Futamata, Koji Imai, Masayuki Oshita, Kaori Fukumori, Nene Naninu, and Kiyoshi Kobayashi.
KJ File is set in a world where unique giant monsters suddenly appear in various places.
Led by Guillermo Marquez, a leading figure in the study of kaiju biology, members of the United Nations Kaiju Observation Team, commonly known as “Kowloons”, are tasked with monitoring and analyzing these giant monsters.