Kouhei Makino, Mana Nagase's former manager, is leading Hoshimi Productions and is looking for a new idol team. During the interviews, two special candidates appear: Kotono Nagase, Mana's younger sister, and Sakura Kawasaki, whose singing voice is strikingly similar to Mana's. They both pass the evaluations, joining a group of other eight aspiring young girls.
The girls move into a shared dormitory, where they practice and learn what it takes to be an idol group. They become a team, working hard to compete in the VENUS Grand Prix. This tournament uses an AI scoring system to determine the most talented idols and was once won by Mana Nagase. The girls are determined to carry on her legacy as they face the challenges of the tough idol industry.