People would be shocked when they saw a little girl slaying people. Aeris Lockhart was just 13 years old when she was asked to be an assassin in order to protect his younger brother from being murdered. That's because her brother will have to take on the 'White Samurai' name in the future, the name of an assassin that feared by most people. She was forced to leave her parents to be train to be stronger, faster, smarter and emotionless than her prey. And she was very surprised to find that her preys were not only human, but also creatures that she never known exists except in the storybooks. She had to bear her father's name until her brother grown up. Until then, she had no choice but to kill those evil creatures or human that she's being paid to kill.