abrv.      name                   type / subname 
-------------------------------------------------------

oav   -   Tenchi Muyo Ryo-oki     Tenchi Muyo Collection
tv    -   Tenchi Muyo TV          Tenchi Muyo Universe
stm   -   Shin Tenchi Muyo        Tenchi in Tokyo (tv)
ps    -   Pretty Sammy            oav
mps   -   Magical Project S       ?
ms    -   Mihoshi Special         oav
tml   -   Tenchi Muyo in Love     movie
mne   -   Manatsu no Eve          Daughter of Darkness (movie)

General Profile:
Tenchi seems like an ordinary type of guy... that is until he gets involved with some ladies from the stars. Tenchi is directly descended from Youshou who was to be emperor of Jurai (before he disappeared), which makes him an able candidate for marriage with Aeka. More or less, all series stem from Tenchi's adventures, and his love triangle (sometimes a love square or multiple sided polygon) with the other girls. Tenchi likes them all, but he can't make up his mind between them all. Throughout all series, Tenchi's personality remains the same, but his abilities and a few characteristics change from series to series.

• Ryo-oki - Tenchi has the ability to generate Light Hawk Wings.
  
• Pretty Sammy: Tenchi is Sasami's brother

General Profile:
Aeka is a somewhat snobby spoiled princess from the planet Jurai, but since she's royalty that's only to be expected. By chance she happens upon Tenchi and falls in love with him. Aeka has a sort of schoolgirl love for him (far more innocent intentions when compared to Ryoko). Aeka is very uptight and proper. She is also extremely temperamental, usually because of Ryoko who knows exactly which buttons to push to make her angry.

• Ryo-oki: Aeka was to wed her half brother Yoshou
  
• Ryo-oki: Aeka was cryogenic frozen during the search for Yoshou
  
• Pretty Sammy: Aeka is the student council president.

General Profile:
Ryoko is a demon/space pirate who was a wanted criminal throughout the galaxy. She is very out spoken, very forward, mischievous, and often times "naughty" (not to mention a sadist). In the OAV Ryoko is FAR more powerful than the others in the Tenchi group. She has the ability to fly, and teleport to locations which she has previously been to. Ryoko adores Tenchi, sake, and annoying Aeka. She also has a tendency to avoid work.

• Ryo-oki: Ryoko was created by Washu and was a servant of Kagato
  
• Ryo-oki: Ryoko harnesses the power of 3 mysterious gems
  
• Ryo-oki: Ryoko can call and control spirits.

General Profile:
Sasami is a royal princess of Jurai and Aeka's little sister. Since she's fairly young, she's very playful, mischievous, and. seems to always be cheerful. Her companion most of the time is Ryo-Ohki. In Pretty Girl Sammy, Sasami is chosen to be the warrior of love by Tsunami, and has many various powers. Pretty Sammy makes appearances in almost all Tenchi series.

• Ryo-oki: Sasami & Tsunami's fates are intertwined...
  
• Pretty Sammy: Sasami is Tenchi's younger sister
  

General Profile:
Washu is the greatest genius in the galaxy (maybe the universe) and has a good all around scientific mind. In the OAV she was imprisoned by Kagato. In the TV series, she was imprisoned at Misaki shrine. Washu's power mainly stems from her mind. Since she's so smart, she can out think just about any opponent. Washu also has a knack for making inventions (which are often prone to go haywire).

• Ryo-oki: Washu is "technically" Ryoko's mother
  
• Ryo-oki: Washu created Ryo-oki
  
• Pretty Sammy: Washu is a school teacher at Tenchi's school.
  

General Profile:
Cheerful, energetic, and smart as a sack of wet rocks... that's Mihoshi. Mihoshi is more or less clueless about pretty much everything, and has a knack for getting into accidents, and making a mess. In the TV series Mihoshi is partnered with Kiyone whom she is very dependent on. Without Kiyone, probably nothing would ever get done right. In the OAV Mihoshi has a special liking for Tenchi.

• Ryo-oki: Mihoshi's grandfather is an important diplomat
  
• Pretty Sammy: Mihoshi is an employee at Sasami's Mothers record store

General Profile:
Kiyone is smart, serious, level headed (unless around Mihoshi), and fairly good at just about anything she does. Kiyone is a determined and dedicated Galaxy Police officer, but unfortunately she ended up partnered with Mihoshi who screws up every opportunity for Kiyone to get promoted. Even though Kiyone resents being partnered with Mihoshi, every now and then she does show some sense of warmth towards her partner.

• Pretty Sammy: Kiyone is an employee at Sasami's Mothers record store

General Profile:
In the OAV the original battleship Ryo-oki was destroyed, and reproduced itself as a cute little creature also known as Ryo-oki. In both series Ryo-oki is Ryoko's partner, but while on Earth she tends to hang around Sasami. In Pretty Sammy, Ryo-oki is the guardian sent to guide Pretty Sammy. Ryo oki loves carrots, and has a fondness for Tenchi

• Shin Tenchi: Ryo-oki can change into a larger mechinized robot
  
• Pretty Sammy: Ryo-oki can talk
  

General Profile:
When Tenchi goes to college in Tokyo his first day, he meets a girl named Sakuya. Sakyua is a fun loving, outgoing, cheerful girl. She is considered to be very popular in college, and it makes everyone wonder why she is so suddenly interested in Tenchi. Sakuya is very good at making instant food (and who isn't? =P ). It doesn't take long before she falls in love with Tenchi. Although very friendly, at times she seems like sort of an air head.

General Profile:
In the OAV, Tsunami is the space tree for the most powerful of Jurai's battle ships, capable of generating the ten Wings of the Light Hawk. Tsunami also has a human incarnation (so I guess she's not REALLY a space tree). The extent of Tsunami's power isn't really known, but if Tenchi can thwart black holes with 3 Light Hawk Wings, imagine what Tsunami can do with ten!
In Pretty Sammy (and Magical Project S), Tsunami is a candidate to become the queen of the magical kingdom of Juraidom. In order for her to become queen, she must restore the balance of good in the universe. For this, she selects Sasami to become her champion of good - Magical Girl Pretty Sammy. The main difference between Tsunami in Pretty Sammy, and Magical Project S, is that in MPS, Tsunami is sort of an air head.

General Profile:
Achika is the mother of Tenchi. She is a kind gentle hearted girl, and rather shy at times. Achika has within her the power of Jurai, for which, the being known as Kain wishes to destroy her. Achika met Tenchi's father Nobiyuki in high school. It was during the battle with Kain that Achika expended all of her power which shortened her life, and a few years after Tenchi was born, she died. It seems that after her death Nobiyuki became a pervert... why (or how) this happened I really don't know.