In Zawame City (沢芽市 Zawame-shi), a large company known as the Yggdrasill Corporation transformed the once bustling suburban city into a jōkamachi (城下町?, castle town). To escape the resulting feeling of oppression, many of the youth in Zawame formed dance crews called Beat Riders to bring joy back into peoples' lives. Also rising in popularity is the Inves Game, a simulator that uses strange devices known as Lockseeds to summon monsters known as Inves.