Having escaped the many horrors of her village, Saya Kisaragi vows to hunt down the monster responsible and make him pay with his life. As she tears through flesh and bone for her vendetta, she encounters SIRRUT, a group of ingenious hackers, who enlist Saya to help them defeat a common enemy—someone she knows all too well.

Unfortunately, the path she follows is paved with tragedy, as once again, Saya faces betrayal at the hands of those she has come to trust. With her back against the wall, the fearsome monster slayer must fight with all her strength and skill if she is to overcome this final mission and exact vengeance.