To date, there are seventeen volumes in the True Tenchi Muyo! GXP series of light novels. Volume 13 was written by Masaki Kajishima, and has yet to be published outside of the main readership in Japan.
Seina Yamada arrives at the original Earth as seen in Dual! Parallel Trouble Adventure where the crew of the Hoystoke have stolen away with Fuku and the Kamidake. It is revealed that this original Earth is equivalent to Mars by most respects, being far flung enough to discourage tourism and having a lack of useful resources.
Kajishima writes that many in the GXP verse cherish this antiquated world for its role in the first prehistoric space missions throughout the Milky Way galaxy.
Accompanying Seina on this trip is Kirche, who speculates during their arrival that the original Earth system may be lacking in any signs of civilization such as ruins or resource dumps that had already been picked over, because it was caught up in the rigors of the seed project forcing everything and everyone there to be recycled.
Dr. Clay fails to get access to the base computer systems in Tarant Shank's hideout. He is led to a storeroom reserved for his use as an impromptu science lab. While explaining to Tarant that the Hoystoke is in grave danger keeping the actual Fuku aboard. He explains that a better course of action would be to use the clones.
Tarant is already preoccupied with the first failed clone experiment, and seeks to dispose of all of them. Clay is first to detect Seina's concealed presence in orbit over the base.
The pirates react quickly, attacking Seina's position and forcing him to crash land on the planet below. D awakens from the commotion and is brought up to speed.
Kazuki's Harem is apparently active on the planet. Meanwhile, Clay tries to track down Miki, but she evades, causing the base equipment to malfunction as she transfers into one of the cloned Fuku bodies.
Misao interdicts the girls' antics and arrests them on the spot, taking them to the Kuramitsu academy estate. Remarkably, the room intended to hold them for an unspecified amount of time is equipped with super computers that have the highest level of security clearance in that kingdom.
Seina and Kirche fend off more pirate attacks, rescuing some trapped Wau and causing a rockslide to crush some of the pirates in pursuit.
The Wau explain to Seina that their mother is ill, and needs healing herbs but they have not found any yet. More pirates approach their location, so Kirche sticks around to scrounge for herbs while telling Seina to take the Wau children to safety.
Dr. Clay seizes Miki and uses her to hack into the hideout intelligence network. He learns about the PKW, a wave that can bypass or disable Light Hawk Wings.
More antics ensue for the gang, until Kirche, D and Miki are able to break from their respective aggressors and radio for help from Seto's people. As everyone collects their stranded assets and makes to regroup with GP proper, Washu is in the middle of a conversation with Seto about the failed cloning process that she overheard Miki talking about. She explains that Fuku clones cannot do most of the Cabbit's usual abilities, such as transforming to humanoid form or other complex tasks. Bureaucrats impose on the getaway effort, detaining Airi's staff in Galaxy Federation court proceedings. D acknowledges to Seina that working under his charge ultimately grants the original Earth solar system to his care, and that it potentially could be declared an independent power with the help of Fuku and the Kamidake to back it.
Miki is reunited with Hiroshi, who was among those bogged down with Galaxy Federation inquiries.