.hack//Legend of the Twilight

Tsurugi Tatsuno is a boy who competes in Virtual Digimon Battle tournaments. When a Kuwagamon appeared in the Real World, his Greymon came to life and protected him. Tsurugi is summoned to the Digital World by Piximon to save the Digital World from the evil Barbamon. Since his Digimon has a hexagon shape on him, it's an Illegal Digimon, meaning that Digimon bearing such symbols can help save the Digital World. Tsurugi's Greymon later De-Digivolves to Agumon and they meet other characters destined to save the Digital World from the forces of Barbamon. Now they must stop Barbamon and his minions before they get all the DigiMemories and take over both worlds.

In 2015 a fire at the main CC Corp. building resulted in the loss of a lot of data, and The World was forced to shut down. By splicing in data from what would have been another game, CC Corp was able to rebuild the game system. The next year, "The World R:2" was released, but many old players objected because they were unable to bring over their old characters. However, many new users were drawn in by the new style, and over 12 million copies were sold. Though not a match for the previous version's 20 million users, it became the top-selling netgame on the market." As a result of the new world, four major clans (Kestrel, Lunar Tree, Canard, and Raven) came to power. The clans actions shape 'The World', and most players end up taking one side or another during conflicts. G.U.+ follows the player Haseo, a powerful PKKer known as "The Terror of Death". Haseo is obsessed with an infamous PKer known only as "Tri-Edge" who attacked a close friend of his sometime in the past. Follow Haseo's search for Tri-Edge, and his eventual inclusion in a mysterious group known as "G.U." - [Wikipedia](https://en.wikipedia.org/wiki/.hack//G.U.%2B)

Welcome to The World, the most advanced online game ever created. Fourteen-year-old twins Rena and Shugo are two middle-school students who enter The World as level-one game characters–and now they're ready to take on anything…or so they think. When Shugo's character dies, he is transported to another level where he is entrusted to bear the Twilight Bracelet by the mysterious Aura. Shugo must find out who Aura is and why she gave him this powerful weapon to protect his sister from the dangers in The World. The manga has been re-edited in Japan into two big volumes called "Complete Edition" ([I](https://www.kadokawa.co.jp/product/201011000008/) & [II](https://www.kadokawa.co.jp/product/201010000605/)) including some bonuses and a new short story. - [Wikipedia](https://en.wikipedia.org/wiki/.hack//Legend_of_the_Twilight)