Ruri is a very serious and protective Jumi knight. He often has to search for his partner, Pearl, who commonly gets lost. He may seem cold, but he truly does worry about his comrades. He and Pearl are on a quest to find others of their kind and to find out what happened to the Bejeweled City. Ruri is a Jumi, which is a person who has a jewel core for a heart, which is visible on their chest.