Ayeka is the oldest princess of the royal family of the planet Jurai.
When Ayeka was still a young child, (which would be several hundred years ago for someone of her lifeline), Ayeka was engaged to be married to her older half brother Yosho. (Yuck!) Ayeka was very happy with that arrangement because she's in love with Yosho. When he leaves to hunt down Ryoko, she spends time in the Ry-oh so she can stay exactly as she is at that moment. She doesn't want Yosho to not recognize her.
She comes to Earth searching for her brother and ends up getting involoved in a chase after Ryoko. Both of the ships end up crashing, and try as she might, she wasn't able to salvage anything from the ruins. She and her younger sister, Sasami, were stranded.
Eventually, Ayeka and Sasami moves in with Tenchi, and Ayeka develops a big crush on him. She sees Ryoko as being her mortal enemy, and fights her at every opportunity, hoping to show her up and win Tenchi's love. But unfortunately for Tenchi, she is as bad a housekeeper and cook as Ryoko is. Oops.
Ayeka has no powers to boast of, unlike Ryoko or Washu. However, she does have several guards to protect her, and a costume that can enable her to fly and hit enemies with an immense force.
She also has several gadgets that helps her prevent Ryoko from going to close to Tenchi. One such instrument would be the gadget she had installed inside of Tenchi's room. If anyone would enter the room without knocking first, he/she would be automatically thrown into a nearby lake. It would be a pretty cool gadget to have. If it would ever work properly, that is.
