We present a Janken (rock-paper-scissors) system with 100 % winning rate by exploiting high-speed vision. This system is capable of performing recognition and motion at speeds far beyond what is humanly possible. Based on the result of the visual recognition, the system can distinguish between rock, paper and scissors at high speed. The delay between this recognition and robot hand motion is low enough for a human to perceive the system's motions as being done simultaneously with the human’s.