Ryo-Ohki is basically a sister of Ryoko with their mother being Washu and their father being Mass. Ryo-Ohki is also a cabbit. That is half rabbit, half cat. Ryo-Ohki has been Ryoko’s spaceship ever since her creation. Her power is so close to Jurain ships that she went right into Jurai unnoticed until Ryoko started attacking.

When Ryoko was captured in the Masaki Shrine, Ryo-Ohki was hidden on earth in a lake. Ryoko then summoned her when Ryoko and Ayeka decided to have a confrontation (I use that loosely). Ryo-Ohki was destroyed in the collision resulting when Ryoko used her ship to pull down Ryu-oh to earth. Although Ryo-Ohki didn’t sustain much damage (because Ryu-oh took the brunt of it) she died because her life span was getting at an end. Ryo-Ohki (first generation) felt her weakness in her power and decided to let herself evolve in her second generation. In order to help herself evolve, Ryo-Ohki took in Ryu-oh to reinforce her offensive capability. So she let herself die and reproduced into the cabbit that we know now.

Why is Ryo-Ohki in the form of a cabbit and not a space ship? Here’s the reason why. Before episode one, there was a cat called Chibi that lay dying on Tenchi’s doorstep. When Tenchi found her, he took her in and nursed her back to health. In reality, Ryoko saw how hurt Tenchi would be if Chibi died (in her astral form because she was still imprisoned in the shrine) so, with the last energy in her makeshift gem, she helped Chibi regain health. When Ryoko broke free from her prison, the only thing that she could do was to assimilate the cat with Ryo-Ohki. That is why Ryo-Ohki is half cat.

The jewel on Ryo-Ohki’s forehead, what is it? Well, for one thing, it doesn’t serve the same purpose as Ryoko’s gems. The gem on her forehead helps her keep a telepathic connection between Ryoko, herself, and Washu.