Nono Hana is an eighth-grade student who aspires to become a fashionable and responsible big sister figure. She consistently wears a pleasant expression and enjoys exploring new things. One day, while on her way to search for something exciting, Hana encounters a baby named Hug-tan and his guardian fairy Harry, who had fallen from the sky. Suddenly, an evil organization called Dark Tomorrow emerges, seeking to seize Hug-tan's Mirai Crystal. In order to safeguard Hug-tan and everyone else's future, Hana wishes for help and is granted it as she receives a Mirai Crystal and transforms into Cure Yell. The world is now inundated with Tomorrow Powerer, which refers to the ability to create a bright tomorrow crystallized into Mirai Crystals. If these are stolen, everyone's future will cease to exist. As Cure Yell, Hana will do her utmost to protect Hug-tan and secure everyone's future.