If you haven't guessed by the title Tenchi is the main character of this series. He lived on earth for 17 years until his perception of his life greatly changed...
Ever since he was young his grandfather trained him in the art of swordplay each summer while he was off from school. He trained less at home in the suburbs every night. He never knew why his grandfather trained him but he just accepted it. Tenchi grew up most of his life without his mother, who died when he was very young. He was raised by his father, Noboyuki and his grandfather Katsuhito. Because of this Tenchi gained a sense of responsibility.
His grandfather sensed great power in Tenchi. He learned his lessons well and became an excellent swordsman. Tenchi can create up to three Lighthawk wings. I'm not sure if he was born with this ability or if gained it after being regenerated by Tsunami.
Tenchi has a kind heart and is a bit indecisive when it comes to women. He has women who are interested in him all around him but he's yet to follow through with any of them. Ryoko, Ayeka, Sasami, Mihoshi, and Washu all have some interest for Tenchi.