Ryusei Shidou is an eccentric and violent illegal street racer with a unique perspective. He believes street racing is a biological drive to leave his mark on the world and gets excited by high-level competition. While prone to aggression and toxic behavior, he can also be friendly and affectionate when shown a different side of soccer. Under the influence of Sae Itoshi, he becomes more openly confrontational but learns to control his anger over time.