Tenchi Muyo means basically heaven and earth ( I think :) ). The series is about a normal Japanese high schoolboy whose life is interrupted one day when a bunch of girls who crash land right in front of his house. From the his home life will never be the same. So far there is the Tenchi Universe (TV series) Tenchi Muyo in Love, Tenchi Muyo Daughter of Darkness, and Tenchi Muyo OVA's.
The Men:
Tenchi: the main character and the one gifted with strong Jurai powers. The girls all love him especially Ryoko and Ayeka.
Naboyuki: Tenchi's father and a all-around pervert. Even though in a tight pinch he can be a pretty cool guy.
Grandfather: he lefted Jurai long ago and could have been the Emperor or maybe will be(tv series or ova's). Pretty stong in Jurai powers he married and earthling and through her had a daughter named Achica and later a grandson named Tenchi.
The Women:
Achika: Tenchi's mother. She seems to have strong Jurai powers and in Tenchi Muyo in Love her powers seemed even stronger then Tenchi's. She dies a few years later after Tenchi's birth, little is known why she died, but Tenchi thinks its because she used her powers to battle Kain.
Ryoko: is basically a space pirate who has amazing powers (from three gems that she wears ova series). She can teleport through any solid object, summon demons, split herself into 2 beings, make an energy sword, and throw energy bolts from her hands.
Ryooki: is a cabbit (half rabbit and cat), who is I guess a pet of Ryoko's but very intelligent. She basically can transform into a battleship, teleport through walls, turn into a human (because of the mass ova series), and can speak with only Ryoko.
Ayeka (Aeka): princess of the house of Jurai. She has pretty cool powers being able to make miniature figures of azaka and comadake which in turn can be either offensive or defensive power.
Sasami: is the second princess of Jurai. Don't know much about her power except that in the ova's she almost died but assimilated with Sunami (the ship of Jurai) and those to can merge together to form a powerful battleship.
Mihoshi: oh lord the goofy ball of the group. She is part of the galaxy space police and a bad one at that.
Kiyone: a damn good officer until she met Mihoshi her partner. Serious and calm in any situation she would probably be at the top of her rank if not for her partner. Only appears in the movies and tv series.
Washu: the greatest scientific genius in the universe from what she says. At one time she attended the Scientific Academy but was kicked out. Brilliant in a lot of ways yet a little strange, great with inventions, she is trying to conquer the galaxy.