Shuu is loud and outgoing. He's best friends with Ishikawa. He likes to play pranks on people and tends to be the one starting the games or activities done by the group. Everyone in the group finds Shuu to be annoying. He's like the human form of a green ball of energy, but He is different at home, acting subdued and cold towards his younger sister, Motoko. However, despite this cold attitude, he still loves his sister very much and tries to help in whatever way he can.