.hack//G.U. Vol. 1//Rebirth

.hack//G.U. Vol.1//Rebirth (.hack//G.U. Vol.1 再誕) is the first of the three part series that launches .hack Conglomerate. Vol.1 Rebirth, was released in Japan on May 18, 2006 and on October 24, 2006 in North America. The game takes place after the .hack//Roots anime series, which serves as its prologue.

Due to a fire at the CC Corporation building, the MMORPG "The World" had to be shut down. CC Corp. salvaged some of the data and merged it with another project, creating a new version of the game called "The World R:2", which is where the .hack//G.U. series takes place. Many players of the original The World quit the game after learning that their old character data had been destroyed. Major guilds became a large part of the game and most players took sides; this led to the game being overrun with Player Killers. Vol.1 Rebirth follows Haseo, an Adept Rogue.