Etsuko Satoda is a middle-aged teacher who is still actively teaching at the JCC school. When she was younger, she was a master martial artist assassin—an aikido master. She was the first person to use aikido to kill. She came back from every one of her missions unscathed. She was once recruited to be a member of the order to be part of a special force within JAA (Japan Assassin Association) comprised of elite assassins, but she refuse then choose instead her teaching career.