In the dead of night, a blue-haired, blue-eyed girl dressed as a boy broke into the residence of death row inmates. As a killer in an assassination organization, she had her own rules for killing. One day, she suddenly discovered that what she had been killing were not humans, but monsters. To protect the land she had sworn to defend, she began investigating a hidden corner of this world. As her missions continued, the people around her told her they had all come for the sake of her past life.
"You think you can go back to your old life after learning all this?"
"I'm looking for someone important. You have something that belongs to someone important to me."
