For the first time in the Ultraman franchise’s history, the new show will center on two protagonists who are brothers. Yūya Hirata plays older brother Katsumi Minato, who can transform into Ultraman Rosso. Ryōsuke Koike plays younger brother Isami Minato, who can transform into Ultraman Blu.
Both brothers live with their family, which includes a younger sister who attends an all-girls school, and their father who runs a boutique shop. One day, the two brothers find the R/B Gyro and R/B Crystal. The R/B Gyro transforms Katsumi into Ultraman Rosso, which gives him control over the fire element, while R/B Crystal transforms Isami into Ultraman Blu, which gives him control over the water element. Though both brothers sometimes butt heads, they fight monsters together.