Koji Shiraishi (白石 晃士, Shiraishi Koji) was born and raised in Fukuoka, Japan. After graduating from Kyushu Sangyo University with a degree in film production, he worked as an assistant director on films such as Gakuryu Ishii's August in the Water and Shinobu Yaguchi's WATER BOYS.

He names Gakuryu Ishii as his favorite Japanese director, and his favorite film is Ishii's 1980 Crazy Thunder Road. Among other directors he admires are John Carpenter, Brian De Palma, Abbas Kiarostami, and Sam Raimi, and among films he likes the original Dawn of the Dead (1978), The Evil Dead (1981), Evil Dead II: Dawn of the Dead (1987), The Thing (1982), and The Texas Chain Saw Massacre (1974).