Kagato was once a student of Professor Washu at the Science Academy and was believed to be of some sort of descendant of Jurai. After Washu’s creation of Ryoko, Kagato rebelled and captured Washu. Washu’s imprisonment then was put in the alternate dimension between the levels of Soja, Kagato’s ship.

Because of Kagato’s love of power, he tried to find the secret of the gems created for Ryoko and succeeded. Although he was able to mimic the gem’s power, he wasn’t able to mimic their compact size and they consequently became part of Soja. One advantage of his mock gems though, are that they can draw on more power at one time than Ryoko’s. Along with Kagato’s love of power is his desire to capture, control, and find out the secret of Tsunami, Jurai’s most powerful ship.

Since Kagato’s mock gems were more powerful than Ryoko’s, he was able to control Ryoko and force her to lead an attack against the planet Jurai. His plan was to use Ryoko as a distraction so that he could lead an individual attack against Tsunami. His plans were foiled when Yosho went after Ryoko and cut off her gems thus severing all contact from Kagato to Ryoko. In search of Yosho, Ryoko, and Tsunami, Kagato approaches Earth with the plan of drawing out Tsunami with a direct attack on earth. He ends up kidnapping Ryoko which leads Tenchi to go after her. In the end, Kagato reaches his end when Tenchi summons the Light Hawk Wings and kills Kagato.