Washu Hakubi, the greatest scientific genius in the universe, is a key character in the Tenchi Muyo! metaseries. 

In the Tenchi Muyo OVA Washu is one of the Chousin; three sister goddesses who created the multiverse, the other two being, Tsunami and Tokimi

In the Magical Girl Pretty Sammy OVA, she is an Earth child prodigy known as Washu Kobayashi. Graduating from M.I.T. at eleven years old, she became the high school science teacher at Raioh Academy.

In Magical Project S, Washu Fitzgerald Kobayashi is an American and. She is a teacher at Sasami school and the first human to be fully aware of Sasami's secret identity as Pretty Sammy and only moved in next door to Sasami's house to keep an eye on Sasami and analyze her magic for research purposes. 

Tenchi Masaki may be a 17-year-old young man in rural Japan, but little does he know how bad his day will be getting. When a space pirate chased by a pair of Galaxy Police officers crash-lands at his grandfather's temple, Tenchi is sucked into a new adventure that will literally blast him off into outer space and beyond. 
(Source: Anime News Network)

Flávia Fernandes Saddy is a Brazilian sports announcer and voice actress.

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 deal with five alien girls who each have some sort of romantic interest in him. 
(Source: Anime News Network)

She's the sister of another famous Italian voice actress, [Ilaria Latini](https://anilist.co/staff/95766/Ilaria-Latini).

Seina Yamada is unlucky... so unlucky that when he stumbles upon a recruiter looking for his senpai Tenchi he gets taken instead. Forced into the Galaxy Police, his luck begins to change. A natural to randomly jumping near pirates, he is assigned his own decoy to draw out pirates. His luck brings him into the lives of four women who have a habit of cancelling out his bad luck, turning it into good. Armed with this luck, they pilot the most powerful ships in the Tenchi Universe to defeat the Da Ruma pirates. Now the only uncertainty is whether the sexy Amane Kaunaq, a former model turned into a GP detective, sturdy Kiriko Masaki, who has known Seina for years, the mysterious Ryoko Balta, a former pirate named after the legendary one, or the child-like Neju Na Melmas, a powerful 2000 year-old priestess, will win Seina.
 
(Source: Anime News Network)

To save the universe, Tenchi is going undercover—at an all-girl’s school! Can he survive the attention of cute girls at this not-so-ordinary school and put the timelines back into balance? Join the harem and fun in this series of shorts! 
(Source: Crunchyroll)
 
Note: The anime is set in Takahashi, the sponsors for the show, as the city hopes fans will come on a "pilgrimage" to see the setting of the anime, and plans to sell goods and host related events.

An American stage, television, and voice actress who has provided English language voices for Japanese anime shows, animation, and video games. Some of her major roles are Kallen Stadtfeld in the Code Geass series, Miyuki Takara in Lucky Star, Nina Fortner in Monster, Rider in Studio Deen's Fate/stay night, Suigintou the first Rozen Maiden doll in Rozen Maiden, Sawako Yamanaka in K-On!, Sola-Ui Nuada-Re Sophia-Ri in Fate/Zero, and Momo Hinamori and Soi Fon in Bleach.

In live-action productions, she portrayed Jolene in the television show Weeds.

This OVA series gives the viewer more in-depth details on Sasami, Washu, and Ryo-ohki, as well as introducing members of the Juraian royal family. 
(Source: Anime News Network)

Tenchi decides to move to Tokyo in order to lead a normal life in the big city. While in Tokyo, Tenchi meets a girl named Sakuya. They soon fall in love, but as it turns out, a dark sinister force has created Sakuya to get at Tenchi and rule the earth. Now Tenchi must balance love, friends, and life while defending the earth one last time.
 
(Source: Anime News Network)

The demonic space criminal Kain has escaped from prison and destroyed the Galaxy Police headquarters. To ensure that the Jurai will not stop him, Kain travels back to 1970 to eliminate Tenchi's mother before he is even born. Now, Tenchi and the gang must travel to the past to stop him before he ceases to exist. 
(Source: Anime News Network)

A few days after Kagato is defeted everything returns to normal. Ryoko finds Mihoshi and Sasami reading shojo manga which Sasami tells that they are guides to tell how to win a boy Earth style. So Ryoko decides to try to use ideas from manga to win Tenchi. Ayeka finds out what she's doing and starts using the manga to win Tenchi as well. 
(Source: Anime News Network)

Tenchi walks into the mountains and disappears. After searching all over Japan for Tenchi, Ayeka and Ryoko finally locate him in Tokyo where he is now several years older. Tenchi appears to be in a parallel world with a mysterious girl, named Haruna, and doesn't remember Ayeka and Ryoko! What is the mysterious connection between Haruna and Tenchi's grandfather, Yosho? It's up to Ayeka and Ryoko to discover what Haruna wants with Tenchi and to rescue him before he disappears forever! 
 
(Source: Geneon Entertainment)

Continuing right where the last OVA series left off, the mysterious Lady Tokimi dispatches the warrior Z to Earth in order to learn more about Tenchi and his connection to Washu and Tsunami. Z is ordered not to lay a hand on Tenchi, but he may have his own agenda as he quickly sets about making trouble for our hero. Meanwhile, Tenchi's father and grandfather come to the decision that it may be time for Tenchi to learn even more about his past and his Jurian heritage. And the arrival of a couple of new female residents to the Masaki household threatens to upset the balance and inflame the rivalry over Tenchi's already decidedly divided affection. 
(Source: Anime News Network)

A girl, Mayuka, appears one day claiming to be Tenchi's daughter, much to the shock of the Masaki household. Chaos ensues as Washu attempts to discover Mayuka's background, and the girls adjust to the new presence at their home. The result of her appearance reaches back into the past, and puts Tenchi in danger. Tenchi and Ryoko must travel into the realm of a demon called Yuzuha in order to try and set things right, but their task is not an easy one.
 
(Source: Anime News Network)

The trouble and fun began when ordinary teenager Tenchi Masaki inadvertently released the legendary demon Ryoko from his grandfather's shrine. Turned out Ryoko was actually a marooned space pirate! Since then, she's become Tenchi's unwanted houseguest, attracting a host of other troublemaking alien women: Ayeka, a haughty alien pricess; Sasami, her mischievous little sister; and Washu, Ryoko's mad-scientist "mother." Add Ryo-oh-Ki, an adorable little carrot-eating spaceship, and you've got one full Shinto shrine! 

(Source: Viz Media) 

A spin-off of Tenchi OVA 1&amp;2, No need for Tenchi follows the usual hijinx of the Tenchi gang, as well as throwing several new characters in the mix including a Ryoko clone, and Washu's other lab assistant.