Tenchi-ken (Sword Tenchi) and the power possessed by members of Jurai's Royal Family. Sword Tenchi is just a weapon and is not revealed to be a Master Key. Tenchi attends school in the city, but it is a long commute for him because he lives in the mountains of Okayama near his family's shrine with his widowed father, Nobuyuki, and his grandfather, Shinto priest Katsuhito.
Tenchi once again leads an ordinary life until the arrival of Ryoko to his home. Ryoko claims to be being chased by a vicious space pirate who actually turns out to be Galaxy Police detective Mihoshi. After the ordeal, both alien girls are stuck at Tenchi's home without any complaints from Ryoko who falls head over heels for Tenchi.Tenchi in Tokyo, Tenchi's personality and background are different. He has no connections to Jurai and the sword is created from seven gems which he inherited from his late mother. As this series started out intended to be a continuation of Tenchi Universe, the girls are all with Tenchi in the house already by the start of the series. He's also much less tolerant with the girls (especially Ayeka and Ryoko), often scolding them for causing him trouble.
However, this idea of continuation was soon abandoned, and episode 7 is used as a flashback episode, revealing that one night, Ryoko and Washu came down to Earth trying to escape with the Jurai Light Stone which they'd stolen, with Kiyone, Mihoshi, Ayeka, and Sasami by proxy in hot pursuit, leading all six of them to end up at the woods near the Shrine and house. In the ensuing hijinks, Ryoko ends up absorbing the Light Stone and transforming into a monstrous form around the same time as Tenchi ends up seeing the commotion and meeting the girls, and the gem sword awakens itself as a weapon, with Tenchi forced to use it against Ryoko in self-defense, presumably almost killing her.
After Tenchi nursed the girls and especially Ryoko back to health, Ryoko had separated the gems to prevent the sword from being used against her again. Each of the six girls took one of the gems as a keepsake. However, in the first episode of the series, Tenchi moved to Tokyo to train as a Shinto priest under a friend of his grandfather's, hence the series' title. Eventually, due to the chaos surrounding the girls' visits through the inter-dimensional portal Washu created, along with Tenchi's blooming relationship with classmate Sakuya Kumashiro which did not go over well with Ryoko and Ayeka at all, Tenchi got tired of the girls coming over and ordered them never to disturb him again, and sealing the portal entrance with his blanket before asking Washu to remove the portal completely. This led to the house growing apart and the girls going in at least four separate directions midway through the series.
At the end of the series, Tenchi finds out that his family, the Masaki, are the Planet Guardians whose job is to protect the planet from evil forces when the need arises. Although it was hard for Tenchi after learning about Sakuya's true identity as a manifestation of the warped mutant Juraian Yugi's shadow, Tenchi was able to unite the gems together and chose to confront Yugi alone, feeling that he was partly responsible for what happened. With some help from Ryoko, Ayeka, Mihoshi, and Kiyone, Tenchi caught up to Yugi and chose to spare her and give her a second chance. Tenchi explained she should have come to the Masaki Shrine in the first place and become friends with him and the others rather than to wallow away in loneliness. After the final battle, Tenchi moves back to the Masaki Shrine, Yugi agreeing to be sealed in the Masaki Cave until she was mature enough to control her powers.
In the Pretty Sammy OAV series, Tenchi Kawai (河合 天地, Kawai Tenchi) (as he is known in the show) is Sasami's older brother and a high school student. He is the center of attention for his classmates, Ryoko Orikasa and Ayeka Takada, to the point where they would fight each other for his affections. When Ryoko and Ayeka were transformed by Pixy Misa into Love Love Monsters, they began to fight over him for their affections, until Pretty Sammy intervened. When Pretty Sammy was having trouble against the Ryoko and Ayeka Love Love Monsters, Tenchi was able to get through to them by apologizing to them for not choosing between them. Even after Sammy turned them back to normal Tenchi still had to deal with Ryoko and Ayeka's bickering as he doesn't understand true love yet.
In Magical Project S (Pretty Sammy TV), he only appears in Episode 12 and is known as Tenchi Masaki, a director of Blue Sky Cool Rangers, a Super Sentai or to american audiences Power Rangers-style TV series. Tenchi was having problems with the production as he was starting out as a director, until Sasami decided to help by guest starring on a Cool Rangers episode as Pretty Sammy. This helped save his career. Sasami developed a crush on him, but was heartbroken, after she learned that Tenchi already has a girlfriend, and that he was moving away when he was given a job offer as a theatrical director.