Ryu Terui is a major character in the tokusatsu series Kamen Rider W. He is the superintendent of the police force in Fuuto and becomes Kamen Rider Accel, an ally and sometimes rival to the main protagonists. Ryu is known for his serious and determined personality, driven by a desire to avenge his family's death. Throughout the series, he grows from a vengeful loner into a reliable comrade, playing a crucial role in helping defeat various Dopant threats.