One day on a chilly December, Kamijou Touma and the others are planning to go to a family restaurant, however they stop at an event that hosts a beta testing of the newest game called 'Legend of Astrum', an VRMMORPG. Index gets tempted to play it and they 'luckily' were chosen to be one of the beta testers. Thus they log in...but later they notice it. They cannot log out anymore.