Set in 12090 AD. While making her rounds, the whip-wielding seventeen-year-old Doris Lang, daughter of a deceased werewolf hunter, is attacked by Count Magnus Lee, the long-vanished vampire lord said to be over 10,000 years old.

After the unsustainable growth of the human population on Earth, the United Nations has opted to colonize Mars. During this expedition, the humans discovered two alien technologies: The Bacillus virus and the Crusnik nanomachines.

In the year 2022, the gaming industry has reached a new height after the development of the NerveGear, a helmet-like controller that allows the user to fully dive their senses into the world of virtual reality. After a closed beta with only 1,000 testers, the Virtual Reality MMORPG Sword Art Online is launched.