The story follows three girls, Mai Minase, Yuki Aihara, and Kyoko Tohno, and a former CC Corp. director of the Japanese version of The World, Junichiro Tokuoka. They investigate as to why several people have fallen into a coma while playing the game. The amine starts with the collapse of Mai and her boyfriend, (Tomonari Kasumi). It is soon revealed that she heard a certain sound (which is also present at important points in .hack//Sign) shortly before collapsing. She later wakes up to the same sound, the sound that tunes. “A In C Minor”.
Through the knowledge of all the the characters, the constantly search for the answer to why there have been so many victims due to “The World”. Will they be able to battle something that doesn’t even exist in the real world?