The self-proclaimed hero, Neptune, awakes in a familiar world, but has no recollection of anything other than her name. With the help of a mysterious girl named Chrome, as well as three other familiar faces beloved in the Neptunia™ series, Neptune embarks on a journey through the mysterious dimension to try to regain her memory.​Little do they know, the world they inhabit is under attack by an enemy who wants to take civilization back to the time where 2D reigns supreme. ​Can Neptune and her friends save the world and 3D games as we know it, or will they be flattened into two dimensions forever?