The story takes place in "Nearland," a theme park where "dreams, hope, and science" exist together as an AI theme park. The theme park is where the first automated human-type AI is born. Vivy is an AI who sings on stage for park attendees every day, as it is her directive to "make everyone happy through song." She performs wholeheartedly for the attendees in the park. One day, an AI named Matsumoto appears before her. He says he has come from 100 years in the future with the directive of "working with Vivy to correct history, and to stop the war between AI and humans that breaks out 100 years from now." The 100-year journey of the AI songstress Vivy begins.