An ambitious amphibian sea-creature wants to venture into the human world. Her dream to evolve into the perfect individual is so strong that she overcomes the physical boundaries of her fish-body and transforms into a human being. But even as a young woman she remains restless. Will she ever be content?

Taking place after the events of the Kamen Rider Gotchard TV series, the time is approaching for each of them to leave for their individual tomorrows. After graduating from high school, Houtaro Ichinose's dream remains the same: to become a big-time alchemist. Renge Icho and Sabimaru Tsuruhara are also moving on to the next stage. As for Rinne Kudo...