To date, there are seventeen volumes in the True Tenchi Muyo! GXP series of light novels. The very first volume in the series was written by Masaki Kajishima after the airing of the GP anime itself, and has built a steady readership in Japan.
Seina Yamada is taking a slightly more dangerous bike route to go see his friend Kiriko Masaki. He thinks back to his distant relative Tenchi, whose farm recently took on an explosion of carrot growing hectares. Then his bike starts to wobble, and he suspects a flat tire.
As he stops to inspect his bike, he finds himself already at the Masaki estate. He uses water in the nearby pond to check his bicycle tire for the hole. Right then something enormous crashes into the middle of the lake, engulfing Seina.
He nearly drowns, but is revived by a strange blonde woman in a bodysuit. She straightens out his garb, and asks if he was the one waiting to join the GP before handing him an application anyway and quickly leaving.
Seina's immediate family corral him into signing the GP application without giving him a chance to even skim the information pamphlet attached to it.
Seina relents, and eventually retires for the evening, thinking of Kiriko.
When he awakes, thinking he was dreaming all of the previous events, he finds a relative of Mihoshi watching over him. There is a brief exchange with family members over a video connection. He has many questions, but they will all have to wait.
Seina is given a brief tour, landing him on the bridge of a GP starship. Mihoshi's relative accompanies him, constantly petting his head. Seina is convinced that this is an elaborate hoax that was so well done it even involved his family connections.
His thoughts derail when Mihoshi's relative, then identified as Mitoto-sama, begins debating with the ship's captain on how to convince Seina that he is aboard a starship.
They disengage the ship's gravity, and Seina flails about before finally accepting that he is indeed in outer space. When it is turned back on again, he accidentally opens the ship's hailing channel which alerts nearby pirates.
As far as he is aware, the ship's commanding officer Onnainin and the Seniwan assistant Mitoto are aliens. He asks Mitoto about her rank in this organization, and Mitoto clarifies that she is just there to clean things. Seina cannot help but notice how dirty the ship's bridge actually is and that she is being kept from actually cleaning.
After a bit, Seina learns how to work the ship's communications, and considers dialing for home. He imagines how to impress Kiriko with his new line of work. But when the Masaki residence receives his call, it sounds like the answering machine. However, a video springs up, and Seina realizes it is his classmate Kai. Kai cannot see the video on his end, and is shocked when Seina plays a prank on him using the video feed's vantage point.
The ship prepares to enter hyperspace, so Seina must hang up and brace for the unexpected. It is a complete letdown. After, he is asked to retire to his quarters, giving him a chance to phone Kiriko instead of Kai this time.
When the call connects, he is bounced around over to several family members and it appears Kiriko just left the locale. But she returns during Seina's frantic instructions, and as she takes the call it disconnects as the ship is put under emergency lockdown. The ship is under attack, trailed earlier by pirates receiving its steady hailing.
Seina rushes to the bridge. Onnainin is convinced this encounter was highly unlikely.
After more pirates join the fight, the GP ship intends to retreat. It is chased through several hyperspace jumps until it can no longer jump due to being too close to Radi Shank's ship.
Fortunately, Seto Kamiki Jurai appears in her resplendent royal ship, and shuts down the enemy pirate activities.
Seina discovers firsthand the ornate layout and devastating capabilities of a Juraian Royal Ship. It is identified as the Mikagami, Seto's personal ship. Crew members accidentally let slip about her reputation, that she is none other than the devil princess of Jurai.
Outside of the area of effect of the Mikagami's signature attack, Ryoko Balta assesses the aftermath. They are missing some of their quarry, but dare not intrude on the current Juraian presence.
Seina meets Seto in person, after getting to know a group of four of her staff members for a while. Repairs are then underway for the damage sustained during the GP ship's escapade.
Seina discovers that the Mikagami's interior is detached from normal space, allowing adequate room for a standalone biosphere comparable to actual planets. It is unquestionably vast for something serving as living quarters for the Mikagami's minimal crew.
While aboard the Mikagami, Seina is shown to a guesthouse. Its dimensions approach half a football field in any direction, allowing for more furnishings than a visiting guest would know what to do with. He soon takes the opportunity to phone his relatives back home.
As the dust settles, Seto grants Seina a chance to stay in space by joining the Galaxy Police. She then hails Ryoko Balta's ship in the distance and beckons her crew to come meet Seina. Seto leaves to attend to business, while Balta is surprised by the kind of person Seina is.
Eventually, Seina is received at the GXP's immigration office. While his thoughts dwell on the promise he made to Seto, he is amazed to find Kiriko working behind the desk. Kiriko is outraged that he was whisked into GP training due to Amane's mishandling, while Amane is pleased to see her account replenished with the completed referral.
After a brief transfer, Seina is introduced to Airi and her associate Seiryo, who has a prejudice against Earthlings but was appointed to teach Seina during the next leg of his training with the GP. Seina then goes with Airi to try on uniforms, where he meets Erman. He is then dropped off at his dorm.
There exist a handful of key differences between this light novel and the anime.
- Seina encounters a member of the Shank clan. This is earlier than in the anime.
- Kiriko, Kai and Tenchi are related to Seina and this is clarified in the reading.
- Kiriko is tracking Seina's whereabouts and hacks the system to pose at immigration.
- The infamous Seto scouts encounter Seina before the aftermath of the first battle.
- These scouts receive more attention by the author, such as fleshed out personalities.
- Seto was caught up in a mirror-aspect paradox, which Seina disrupts upon meeting her.