A brother of Kei and the terrorist of the resistance movement.

In the anime, Ryuu aided a terrorist attack on a shopping mall. He was then in charge of the team whose task is to infiltrate the military hospital, and find any information they can on the new subject, Tetsuo Shima.

In the manga as the story progresses, Ryuu abandons his terrorist roots and becomes more heroic, working with George Yamada and guiding Shotaro Kaneda to Akira's chamber where Tetsuo Shima is held up, but battles with alcoholism.