Little is known about Ryoko's past before her fight with Yosho (Tenchi's grandfather). Before and during the battle she was under the control of Kagato. Who had imprisoned Washu and took Soja. Kagato used Ryoko to lead the first successful attack on Jurai. The power of her gems where like that of the Jurai trees so she was able to slip through Jurai borderers without being noticed. During the attack on Jurai she shot down a ship that crashed into a building leading Sasami to her death. Kagato had sent Ryoko to Jurai to find Tsunami and capture her. She was unable to find Tsunami so she had to retreat. Yosho pursued her and finally caught her on the little planet called Earth. After that she spent 700 years in a cave near the Masaki Shrine.