During Japan's feudal era, a war erupted between two ninja clans: the Byakuro and the Kabusu. One night, the Kabusu launched a fierce assault on the Byakuro castle, hoping to kidnap the clan's infant princess. Their mission failed when a loyal Byakuro ninja fled the attack with the princess and vanished, eventually raising her as a ninja. Several years later, six ninja trainees are assigned a mission to infiltrate the Byakuro castle, now occupied by the Kabusu, and retrieve a sacred scroll to complete their training. However, their skills are tested when they encounter three Kabusu members who use dark sorcery in an attempt to capture the princess once again—who happens to be one of the trainees.