Ryu Terui

Kamen Rider Accel is the second Kamen Rider appearing in Kamen Rider Double after the titular rider himself. His name comes from the English word Accelerate and his primary motifs are the letter A and a motorcycle.

Ryu Terui
Ryu Terui is a Superintendent appointed to the Futo Police force, and is Jinno and Makura's superior. When he first came to Futo he met the mysterious woman, Shroud who provided him the equipment to become Accel. Unlike Shotaro who wants to protect Futo out of his love for the city, Terui does not like Futo and only acts as Accel out of duty to the police and to track down the owner of the enigmatic "W Memory." He tends to say "Let's break away!" whenever he assumes his Rider forms and "Your goal is hopeless!" when executing a Maximum Drive.

His first appearance was a cameo in the ending of Kamen Rider × Kamen Rider Double & Decade Movie Wars 2010 proclaiming that Double isn't the only Kamen Rider in Futo as he holds up the Accel Memory. (Here he is known as the "mysterious man.")

Kamen Rider Accel
Like Double, Ryu Terui transforms through the use of USB Flash Drives-like objects called Gaia Memories and putting them in the AccelDriver but has only one fighting form. He fights through the power of the Accel Memory which he inserts into the Accel Driver. His Maximum Drive is the jumping spinning heel Rider Kick Accel Grand Tour. However, Accel has other powers through the use of the Engine Blade.

Bike Form
The power of the Accel Memory allows Accel to change into a motorcycle-like form called Bike Form. This form is accessed by removing the AccelDriver Buckle from the belt when transformed, it allows Accel to reach speeds of 920 km/h.

AccelDriver
The AccelDriver is Accel's transformation belt. It a third generation Memory Driver Terui received by Shroud. The AccelDriver resembles motorcycle handlebars that control Accel's affects. By inserting the Accel Memory into the Mono Slot and reving the Power Throttle, Ryu Terui transforms into Kamen Rider Accel. By squeezing the Maximum Cluth Lever and reving Power Throttle, Accel intiates his Maximum Drive finisher.

Gaia Memories
Like Double, Accel has his own set of Gaia Memories.
 * Accel Memory: Accel's primary Gaia Memory. This enables Terui to transform into Kamen Rider Accel, access his Maximum Drive, and assume Bike Form
 * Engine Memory: The Engine Memory is a unique Gaia Memory with three different elemental abilities imbued in it based on three types of engines: Jet, Electric, and Steam.

EngineBlade
The EngineBlade is Accel's main weapon. It can be used outside the Rider form but is extremely heavy. Through the use of the Engine Memory, Accel can peform a Maximum Drive finisher with the EngineBlade. Like Double's weapons the EngineBlade can be equipped with Memory Gadgets to perform a new Maximum Drive.

Memory Gadgets
Like Double, Accel has his own Memory Gadget, a device powered by an artifical Gaia Memory called a Giji Memory that allows it to switch between its Gadget Mode and its Live Mode.
 * The Beetle Phone is a mobile phone that swithes between Cell Phone Mode and Beetle Mode with the use of the Beetle Memory. It looks similar to the Stag Phone, except it has a blue Japanese Rhinoceros Beetle design. Prior to its appearance in the series Terui it to spy on the Narumi Detective Agency.

Motorcycle
While not part of Accel's assortment, Ryu Terui rides a Ducati 1198, making him the first Kamen Rider in the Heisei Era not to ride a Honda Motorcycle and a non-Japanese Motorcycle company.