Tenshu is imprisoned and sentenced to death for murdering the men who raped his girlfriend. However, he manages to survive his execution and is presented with an option: face another execution attempt or subject himself to their bizarre and dangerous experiments.
Direction
Kitamura's claustrophobic visual language suffocates beautifully.
Practical Effects
Gross creature effects that CGI could never touch.
Acting
Sakaki's thousand-yard stare carries the entire film.

Director
Ryuhei Kitamura
Trivia, insights & behind the scenes
Based on the manga by Tsutomu Takahashi, adapted after Kitamura's breakout hit Versus (2000).
The film's single-location structure and escalating psychological games directly influenced later J-horror survival films like Circle (2015).