Ryō Mimasaka, known as "Gorgon Shell" (石化の盾, lit. "petrifying shield"), uses "Oshiroibori" (白粉彫り) tattoos, which are almost invisible to the naked eye, to hypnotize the opponent to the point that their metabolism slows down so much that it leads to paralysis. She is very close to Sano Yasuyoshi, having known him from their school days, and works under him. She sacrifices herself to save Sano from being killed by Nike.