Three months after the events of Endless Waltz, Heero is trying to live a 'normal' life, but when he is sucked into a wormhole and dropped into the world of Gamindustri, he is given the mission to help Neptune as they collect the Key Fragments. But this mission could prove to be the most difficult, as Heero will be forced to deal with the growing affections of the girls around him.

In the year 200XX, the Cyber Network has spread to the four corners of the Earth and computers manage every facet of life to make life more convenient. All seems well in this new era of humanity, but when strange occurrences in an MMO began to take affect in the real and cyber worlds, one boy and his NetNavi must fight to protect the real and cyber world from destruction.

Takes place after New Mobile Report Mobile Suit Gundam Neptunia. While working to better the nation of Planeptune, Heero, Neptune and Nepgear are transported to a Gamindustri in an alternate world. With a new world and a new threat, it falls to Neptune and Heero to save Gamindustri once again. Unfortunately for Heero, a new world means new girls who will fight for his affections.