Ryo was originally Bunbo, one of the Seven Great Youma that served the Dark Kingdom until Queen Serenity reincarnated them as normal humans in present day earth.
As a human, he became Ryo Urawa with psychic powers.
He briefly attended Juuban Municipal Junior High School and was gifted with precognitive skills which allowed him to score highly on tests. He had a crush on Ami due to her high intelligence. His powers allowed him to know that he was one of the Seven Great Youma, as well as know Ami's identity as Sailor Mercury. He thus asked Ami to kill him so that he would not harm her, but Ami refused and Sailor Moon healed him.
Following this, he transferred to another school, but later reappeared to warn Ami of a plan by Beryl to revive the Seven Great Youma. He is later seen spending time alone with Ami.
- Due to his role in the plot, he is arguably the only "Victim of the Day" character to star in multiple episodes, and was heavily teased as a romantic interest for Ami in promo materials.