Major characters (protagonists)
A teenager that accidentally releases an alien space pirate, thereby drawing the attention of other space faring individuals. His actions unintentionally cause the destruction of his school and the revelation that he himself is part of the powerful Jurain race, and a member of their royal family. In the 1st OAV it is revealed that he can create Lighthawk Wings (the power of the goddesses and Jurai ships) himself without the aid of a royal tree (Tenchi has no Royal Tree but possesses both Yosho's sword key for tree Funaho and a bracelet to draw power from tree Tsunami) when generating his own Lighthawk Wings, Tenchi can also perform energy-matter conversion.
A creation of the scientist Washu Hakubi (of her own egg and a substance called Masu), Ryoko was a space pirate in the service of Kagato until she was sealed in a cave for 700 years, but was then released by Tenchi Masaki in the first episode. She draws most of her powers from three mysterious gems and is partnered with the cabbit-spaceship Ryo-Ohki.
A princess of the Jurai Royal Family, she is searching the galaxy for her half-brother, Yosho, with her sister Sasami when she detects Ryoko (whom Yosho had been pursuing prior to his disappearance). Her tree-ship Ryu-Oh crashes on Earth, where she reluctantly joins Tenchi and Ryoko.
A princess of the Jurai Royal Family, she tags along on her sister's search for Yosho. It is revealed in the 2nd OAV (though hinted at in the 1st) that in addition to being a Jurain princess, she has also merged with the Goddess Tsunami, which grants the Jurai family its royal trees. Sasami frequently cooks for the household and is paired with the tree-ship Tsunami (the original tree-ship of Goddess Tsunami).
A member of the powerful Kuramitsu family of the Seniwa empire and a Detective of the Galaxy Police (which is also under Kuramitsu control), Mihoshi is prone to clumsyness and can act ditsy, despite being highly intelligent. Mihoshi is distantly related to Washu, and through that lineage has the power of inprobably good luck. She crashes on Earth while looking for Kagato.
A former Director of the Galaxy Academy and ranked among the top scientists in the galaxy, Washu's more recent pursuits involve investigating the three gems (the ones Ryoko were given) and creating lifeforms capable of harnessing their power (of which the Ryoko/Ryo-Ohki combination is one). She was trapped by Kagato and later released by Mihoshi. It is revealed in OAV 3, along with a spinoff media, (and hinted in OAV 2) that Washu is a human manifestation of a sister-goddess to Tsunami and Tokimi.
Noike Kamiki Jurai is the adopted daughter Lady Seto and Tenchi's new fiancee. But that was only a pretense to her actual reason why she's here - to keep an eye on Tenchi, who has somehow gathered five of the most powerful women in the galaxy around him!