Dr. Saotome returns from the dead after being seemingly murdered by Getter pilot Nagare Ryoma and threatens the world with his ultimate creation: the Shin Dragon. Ryoma reluctantly teams up with his former co-pilots Jin Hayato and Tomoe Mushashi to combat Dr. Saotome. The pilots must also deal with the mysterious Invaders, aliens that have the ability to possess humans and warp their flesh to form hideous creatures.

The characters from previous .hack//G.U. Games and .hack//Roots receive an email from Ovan. He is requesting them to go to Hidden Forbidden Festival where is set up a mysterious summer festival. There they find an AIDA Chim Chim who wishes to peacefully co-exist with the other players of The World. It then transforms into the word "Returner", so they assume it to mean that Ovan will return to The World.

As a child, Uta—the Red Hair Pirates' ex-musician and Monkey D. Luffy's childhood friend—promised that she would build a new era of freedom by performing joyful music for the world. Luffy and the Straw Hat Crew arrive at Uta's first ever live concert, where many fans have gathered to enjoy the diva's otherworldly singing. Due to a childhood trauma, Uta bears a deep-seated hatred for pirates; her happy reunion with Luffy is cut short when she learns that he has since become one. Luffy's refusal to change his ways results in Uta unleashing her powers on the Straw Hats. The crew soon learns that their minds have already been trapped in Uta's dream world since the beginning of the concert, while their unconscious bodies remain asleep in the real world. With time quickly running out, the Straw Hats must find a way to escape the nightmare or be trapped in Uta's dream forever.

When a young boy called Hiro finds what appears to be a broken lighter in an empty field, it changes his life forever. This lighter is actually the Gold Lightan, a robot that fell to Earth from the Robot Dimension. When called upon to defend the Earth from Ivalda the Great's evil robots, Gold Lightan transforms into a giant super robot, known as the Golden Warrior. Gold Lightan joins forces with Hiro's and his gang, the One Pack Rangers to protect the Earth from the evil schemes of Ivalda the Great and his armored forces.