Soul, passion, the story of life. The end is approaching for the Underworld, a virtual reality created to further the development the supreme AI known as A.L.I.C.E. The Underworld War pits the Human Realm against the Dark Territory in a fight for their lives. Amidst the chaos, a mysterious dark knight flies in from the Dark Territory with a young girl. Is she the key to a bright future, or will she seal everyone's tragic fate? In this action RPG, players take on the role of Kirito, the main character from the SWORD ART ONLINE anime, and adventure with his friends in order to save the virtual Underworld, where the end is imminent. This is the culmination of the SAO game series, featuring high-speed battles, MMO-like multiplayer, over 40 playable characters, and the largest number of unique endings. If Kirito were present… If Eugeo were alive… In this virtual world that is near its end, experience a new story of life that has never been told before.