664 is a member of the Shadow Garden, being one of the Numbers. She is the leader of a three-person squad consisting of herself, 665, and 666. After 666 becomes queen of the Oriana Kingdom, she works undercover as one of her maids. 664 is a beautiful young female Elf with short blue hair, blue eyes, a small beauty mark just left of center on her forehead, and a short but athletic, slim figure to contrast her from her partner, 665. As a member of Shadow Garden, she wears a dark Slime Bodysuit with gold and white accents on the sides of her chest in a standard issue uniform for new members of Shadow Garden, but started wearing a small cape to denote her position as her team's leader. 664 is a very diligent person who takes her role as platoon leader seriously. Apart from being a leader, 664 is a strict and kind girl as she expects her comrades to have the same dedication to Shadow Garden as her and often reminds them to keep their focus on their objective. However, she is not as extreme as people like Victoria, knowing her limits and prioritizing the safety of her subordinates whilst taking full responsibly for their failures. Also, as per Shadow Garden's policy, she does not pry into her comrades' pasts. Overall, despite her tough exterior, 664 genuinely cares for her comrades, though she is too stubborn to admit it.