Ultraman Blu (ウルトラマンブル Urutoraman Buru) is one of the two main Ultra Heroes of Ultraman R/B, and is the younger brother of Ultraman Rosso and older brother of Ultrawoman Grigio. In the past, he used to have a human form of the same name, but the power of Ultraman had been passed onto Isami Minato in the present day.