When high school girl Yuri Honjo comes to, she’s on the roof of an unknown building. She sees skyscrapers all around her, connected by rope bridges, and realizes she’s in a strange world.

There are masked figures who slaughter everyone trying to escape. The stairs leading down to the ground are blocked, leaving just two choices for Yuri - to be killed by the masked figures or to kill them.
What will Yuri do in order to survive in this unreasonable world, and how will she find her lost brother?

“Don’t think, just give in to it. The rules don’t matter anymore, I’ll crush all of this.”