With Gaoh having stolen the DenLiner and trapping the Imagins onboard, Ryotaro and Hana find themselves trapped in the year 2000 where they meet Ryotaro’s younger self, but Ryotaro is slowly forgetting everything having to do with Den-O! As Gaoh gets closer to his target, the only hope lies with Yuuto’s complex plans and a little bit of luck, or else time itself could fall victim to Gaoh’s evil desires!

Sisters "Manamo" and "Minamo" live separately in Hiroshima and London since the divorce of their parents. The elder sister Manamo lives in Hiroshima with her mother, she is a high school student, but moonlights at a Japanese cabaret-club. After her mother remarries and moves to Yamaguchi Prefecture, Manamo lives by herself in Hiroshima. One day, her younger sister Minamo returns from London to visit Manamo. It is ten years since they have lived together, and they argue every day.