One day, they suddenly appeared out of nowhere. They dominate humans with violence, wielding inhuman power, and are growing into a massive structure. They are an evil organization called Nemesis. Its influence gradually spread, and people began to live their lives, shuddering in fear. However, as if in accord with Nemesis, allies of justice also appeared and turned into a resistance force, obstructing its uprising. The girls simply keep fighting with the organization to help the people without ever revealing their identities. On a certain day, Kagami Aoi came across a mysterious man who was fleeing from the clutches of Nemesis. Just as they were driven to a corner, the man gave her an odd inquiry: "If you have the courage to fight, chant "Brave Ignition"." Fate has chosen the girl. And so she reached out to it as well. "Brave Ignition!"