Ryo-oh-ki is yet another creation of Washu. Using a nutrient body and the Masu, Washu formed her to be able to transform into several different objects. Mainly, a spaceship. She usually remains as a cabbit (cat-rabbit), though, and she has a great love for carrots. She can walk through walls (usually on the second attempt). If she dies in a crash, she regenerates and grows again. Once she transforms again, she spawns many of herself to be crystals that control the ship. This creates a problem of a carrot shortage, and Tenchi works constantly to harvest carrots year round. Ryo-oh-ki starts to like Tenchi and is sorry for her trouble. She wishes to help Tenchi, but is not able. When she meets the Masu, she controls them into a human form to help Tenchi without realizing it. The Masu then try to kill Tenchi, but Ryo-oh-ki throws herself at them and makes herself a part of them. She now carries a humanoid form, but she needs some help walking on hind feet. She can change from anthropormorphic cabbit to regular cabbit in a second.
Ryo-oh-ki enjoys the company of Sasami immensely, and they are almost insepperable. When Tenchi's cousin, Taro, arrives, she is scared out of her wits to get away from him because he likes to bash her around. Ryo-oh-ki is linked telepathically with Ryoko and Washu, but Ryoko needs at least one gem to control Ryo-oh-ki fully. She has admiration for Tenchi, but does not love him outright like the rest of the women.