To date, there are seventeen volumes in the True Tenchi Muyo! GXP series of light novels. Volume 5 was written by Masaki Kajishima, and has yet to be published outside of the main readership in Japan.
Seina's entourage are musing about the recent incursion by Tarrant's forces as they rest up in one of the satellite wings of the GP campus. Then, Kiriko overhears Mikami complaining about troop strength demands from the higher ups. It is noted that the GP has come a long way from simply being the private army of the Kuramitsu clan.
After a brief conversation, they all agree that Seina is the likely target of Tarrant's next raid. They set to work figuring out how to get Seina to act as a decoy in the next mission.
Some while later, Tennyo bumps into Seina and confirms for him that her look-alike, Aunt Kiyone, is very much deceased. Seto observes their get together from a distance, much to Airi's ire.
Elsewhere, Hiroshi tries to explain to Kirche that despite her being an Astral AI, she has a lot of people who care about her and that she should be more confident in her abilities. Kirche takes this to heart, and begins focusing on ways to make Seina's GP days bearable.
Airi, not living down Seto's eavesdropping of her relatives, is wandering about the grounds fuming loudly. Amane breaks from her argument with NB to insist that Airi is very immature.
Tarrant Shank strikes yet again, causing scores of casualties. Seina gets away relatively unscathed, but Amane takes a while to monitor his psychological recovery all the same.