Also known as: 仮面ライダーアクセル
Secondary Rider of Kamen Rider W.
Terui Ryu is a young police superintendent in charge of investigating paranormal crimes. However, he loathes his host city, and only does his job to find the "Man with the W Memory", who killed his family.
Unlike Double, Ryu only needs himself to turn into Accel, a red Rider with the ability to transform into a motorcycle. He also has the ability to transform into the blue, speed-oriented Trial Form, as well as the all-around Booster Form but only in W Returns.