When Ash accidentally travelled into the past thanks to Celebi, Kukui, who didn't know Ash at this point referred to him as the Move Kahuna after witnessing him perform Inferno Overdrive for the first time. During their battle, Ash referred to him as Roarie and Kukui liked the nickname Ash gave him. When they were sheltering from the rain, Ash told Kukui all about the Pokémon League which then inspired Kukui to create one in the future.
