In a futuristic Japan, a man known as ‘Key Man’ has
spread a terrible virus that makes humans into
grotesque beings called Engineers who spout weapons
from any injury. A special task force has been set up to
deal with them. They use violence, cruelty and sadism
and executions to maintain order.
Helping them is Ruka, an expert dispatcher of
Engineers. She is looking for the man who killed her
father who was a policeman. Ruka is told to hunt down
Key Man but he infects her. A nationwide crackdown on
Engineers is ordered after a policeman turned Engineer
wastes an entire precinct in Tokyo.