Mikiya Kokutou is taking a leisurely walk home when he spots a familiar face - Shiki Ryougi standing near a railing amidst the snowfall. It was a scene reminiscent of their first encounter four years ago. While reminiscing about old times and shared memories, Mikiya becomes aware that something is amiss with Shiki. He soon discovers that the person before him is not the same woman he has known, but a completely different entity inhabiting Shiki's body.