One day, Shiro and his little sister, Koyori, who has been permanently crippled after an accident, download a peculiar game called "Strings Dolls." Whenever you have someone in your camera screen, the game allows you to move them around like a puppet. Shiro and Koyori are filled with joy to realize that this magical game can restore her ability to walk, at least temporarily. However, other people use it for much less noble purposes. Among the others who have downloaded the game is a mysterious player called Miyabi, who appears to use the game for PKing. Will Shiro be able to track down those behind this game and find the murderous Miyabi before it's too late?