To date, there are seventeen volumes in the True Tenchi Muyo! GXP series of light novels. The eighth volume in the series was written by Masaki Kajishima and acts as a prelude to some of the key events in episode 16 of the GP anime itself. This volume is only available in Japan.
On this particular morning, Washu and Sasami are busy preparing breakfast. Sasami notes that they are cooking with the same fish found in the nearby pond, which may lead to her requesting a fresh batch of monster protein from Washu as seen in OVA 4. Moments later, Noike reaches Washu through a video exchange and brings to light what Ryo-Ohki has taken to chasing around lately: an Amorphos, a winged interstellar dust nibbler resembling a butterfly. This manner of play led to the Masaki premises becoming a 'Butterfly Chasing Prohibition' zone, so that Ryo-Ohki does not run out into the streets.
Ryo-Ohki and Noike's ship Kyoko arrive from another adventure in space, landing in the pond situated before the Masaki home. Noike then accesses the subspace gate embedded into the pond and stores her ship.
Seina and the gang are likewise bringing up the Masakis in their conversation. They have yet to actually visit with Masaki relatives back on Earth. For now, they have contacted Tenchi's immediate sibling Tennyo as they run errands before doubling back to the Academy proper.
Before the end of the volume, Seina is reminded that the Academy will be in recess soon, allowing him to make good on a trip to see family back on Earth. Ryo-Ohki catches up to them in space, making the acquaintance of the Kamidake and chasing it around through the Chobimaru's innards.