Akuma no Kodoku

The "Worm Toxin"—eerie and chilling—is an occult experiment that involves hundreds of insects. Placed inside a small pot, onlookers watch disturbed as the bugs fight to the death until a lone vermin stands. A demon decides to recreate this experiment by sealing a hundred sorcerers in a "Box from Hell" but discovers that the last two standing are head over heels for each other and refuse to end the game. Disappointed but determined, the demon does everything it can to ensure the lovers betray their feelings.