In the martial world, a legendary technique promises invincibility, the Freedom and Ease Technique. After vanishing for forty years, it has resurfaced, igniting a deadly pursuit. While Robin Newton, its sole inheritor, serves on the battlefield, her enemies target her family at home. They torture her mother and sister for the secret manual. Unaware of their suffering, Robin fights far away. But now, she's returned, and vengeance awaits those who dared harm her family.