Yukimi Kawaki and Lilya Evergreen are involved in a terrible accident after many inexplicable events. They wake up in a world in which they are constantly accompanied by the worst deeds they have committed. These are always felt and are made dependent on how one has lived and how well closed the door is that keeps the monsters of the past behind the door frame. Is there always an enemy behind it, or is there occasionally a friend? Time no longer exists. Rain can feel like a relaxing massage, but also like fire that painfully burns the skin. Kawaki and Lilya get to know themselves in a new way. Will they find the right key to help them find their way back to life?