Seven Seas has licensed a trilogy of light novels titled True Tenchi Muyo!, written by Masaki Kajishima and Yousuke Kuroda. The first volume is planned to release in English on June 19, 2018 in print and digital formats. The three books were published in Japan by Fujimi Shobo from 1997 to 1999.
The Tenchi Muyo! franchise began as a 6-episode anime in 1992, an OVA titled Tenchi Muyo! Ryo-Ohki. Further OVA mini-series followed in 1994, 2003, and 2016-2017. There have also been a couple manga series, a few anime films, and some other light novel spinoffs released in Japan.
Synopsis of the original OVA: Tenchi Masaki was a normal 17-year-old boy until the day he accidentally releases the space pirate, Ryoko from a cave she was sealed in 700 years ago as the people thought she was a demon. In a series of events, four other alien girls show up at the Masaki household as Tenchi learns much of his heritage he never knew about and deals with five alien girls who each have some sort of romantic interest in him.
Seven Seas explained how the True Tenchi Muyo! light novels tie in to the franchise:
Based on the hit Tenchi Muyo!Ryo-Ohki OVA series, this trilogy of canonical light novels explores the lore that shapes the past, present, and future of the sprawling Tenchi Muyo universe. In the first novel, delve deep into the backstory of Emperor Azusa (Ayeka and Sasami's father) while learning what happened immediately following the conclusion of the second OVA series. In the second novel, witness the mysterious past of Tenchi's grandfather Yosho, and how he came to find himself on Earth in the aftermath of Ryoko's attack on Jurai. And in the third and final novel, learn the origin of the super genius Washu and the previously untold life she led as a goddess over 20,000 years before the events of the Tenchi Muyo: Ryo-Ohki series!
Earlier this week, Seven Seas also announced that they will be publishing physical editions of the light novel series How a Realist Hero Rebuilt the Kingdom, which is currently being released digitally by J-Novel Club. So far there are four volumes available to purchase as ebooks, and the fifth volume already has chapters available to J-Novel Club subscribers. There are five volumes out so far in Japan.
The first volume of Realist Hero will be out physically in September 2018. Seven Seas is also publishing paperbacks for other J-Novel Club series, including Grimgar of Fantasy and Ash, Occultic;Nine, Arifureta, and Clockwork Planet.