Ten years before the start of Rolling☆Girls, a massive battle called the Great Tokyo War devastated Japan. Over the course of the war, most of Japan's political and economic leaders vanished, leaving a vacuum of power in their tracks. To restructure the country, Japan was divided into ten territories that soon became independent prefectures, with each vying to conquer its neighbors to become the sole ruler of what was once Japan. Many of the heroes from the Great Tokyo War have taken on leadership roles in the different nations; these individuals are now known as Mosas and lead groups of supports called Mobs.
A young Mob named Nozomi Moritomo is instructed by her Mosa to go on a journey with three of her friends in order to grow stronger and observe the other prefectures. Along the way, these four girls search for moonlight stones, heart-shaped jewels said to give their wearers great power... but will the power of the moonlight stones bring about an era of peace, or will they send the nations plummeting into another abyss of devastation?