Best friends Daichi and Seiji set out on an almost too-good-to-be-true summer vacation, but it quickly turns into a nightmare...

Instead of the island paradise they were expecting, they find themselves trapped in a strange room and forced to participate in an incomprehensible "experiment" demanding that they either harm Daichi physically or Seiji sexually. They'll have to play along to have any hope of escaping with their lives, but that means hurting each other and possibly destroying their friendship—and their minds—in the process.

While Daichi is quick to declare that he'd be just fine less one arm, and Seiji argues for the options that won't leave lasting physical scars, do they really understand the consequences? Can they survive the "experiment" and is survival alone enough?