Drake Watson

"Despair awaits you on the finish line!"

- proclamation after a Maximum Drive

Ryu Terui (照井 竜) is Kamen Rider Accel (仮面ライダーアクセル). He receives his Accel Driver from Shroud.

History
He is a Superintendent appointed to the Futo Police Department's Paranormal Crime Investigation Division (超常犯罪捜査課), and is Mikio Jinno and Shun Makura's superior. Prior to arriving in Futo, Ryu lost his family; his father Ryuji Terui, his mother and his younger sister when a Dopant froze them solid. They shattered at Ryu's touch, killing them. In his final moments, Ryu's father warned him to beware the "Man with the W Memory". Ryu, however, goes the opposite direction and is driven for revenge with the aid of the mysterious Shroud. Because it is the source of Memories, he develops a hatred of Futo and seeing it as a gathering place of all kinds of scum.

Ryu received his heavy Engine Blade from Shroud early on. He spies on the Narumi Detective Agency using his Beetle Phone while he waits for his Driver to be completed. Soon after, a new crime wave starts, eerily similar to his parents' death. Thinking he has finally found his families' murderer, he steps out of hiding, revealing that he has been spying on the Agency. He then gets his Driver and transforms into Kamen Rider Accel for the first time. However, Ryu goes overboard with the case, almost killing an innocent person he believed to be the Dopant. It turns out at the end of the case that the Dopant was Ice Age, and the W Dopant was still at large, putting things in perspective for Ryu.

Though he and Shotaro Hidari clash at first, Ryu becomes an ally to the Narumi Detective Agency when it comes to investigating the Dopant crime wave, as well as picking up some of Shotaro's habits in dealing with Dopants even after losing it upon finally finding his family's killer: the Weather Dopant, Dr. Shinkuro Isaka. After obtaining the Trial Memory from Shroud and learning to use it, Ryu is able to finally take his revenge on the Weather Dopant, using the Trial Maximum Drive to destroy his Gaia Memory, after which Isaka dissolved as a result of his long term abuse of Gaia Memories.

After Isaka's death, Ryu becomes more open to the others and continues his role as a Kamen Rider to fight off the Dopant crime wave prior to learning that it was Shroud who gave Isaka the Weather Memory, though she had no idea that his family would suffer as a result. Furthermore, Ryu learns he has a unique physiology, enabling him to withstand the intense power of certain Gaia Memories and was selected by Shroud because he can resist the Terror Dopant's Terror Field. Because of this, Shroud wants him to assume Shotaro's place as Double using his hatred to enable Double to reach full power. However, Ryu has shown Shroud that he can fight with compassion and does not need to be Double to fight. Furthermore, after Philip's disappearance after Jun Kazu's defeat, Ryu had grown to love Futo with a desire to protect it, overall a complete turnabout from his initial personality.

Although he eventually rejected her advances to stay professional, he eventually started a romantic relationship with landlady/head of the Narumi Detective agency Akiko Narumi. Giving her the affectionate nickname "Chief" (署長) to reference her status at the Agency and to give her authority, which she found cute. During the events of W Forever Akiko tells him the story of how people watch the Fuuto Fireworks and fall in love, and she wants someone to watch it. So, just before he and Shotaro go to fight NEVER, he promises he will watch them with her. He fulfills his promise, and they fall in love. In Movie War Core, Akiko tries to stop him from being a Kamen Rider, saying it was getting in the way of their life (and their wedding day), and causing them too much pain. However, he says he is a Rider to protect her. That, coupled with what she saw through the Memory Memory about her father, drives her to allow him to keep his Driver and Memories. They then marry.

In his Rider form, Ryu tends to say "Now, let's break away!" (さあ、振り切るぜ!) whenever he assumes his Rider forms and states "Despair awaits you (all) at the finish!" (絶望がお前（たち）のゴールだ!) and "[0.1-9.9] seconds, that is the time left until your despair!" (○○秒、それがお前の絶望までのタイムだ！) upon executing a Maximum Drive attack. The words on the back of his jacket read "spiritual state of nothingness makes even fire itself cool" which is a phrase derived from Buddhist philosophy.

Ryu Terui makes a cameo appearance at the end of Kamen Rider × Kamen Rider W & Decade: Movie War 2010 proclaiming that Kamen Rider Double is not the only Kamen Rider in Futo City any more.

Forms
Kamen Rider Accel's ending theme is entitled "Leave all Behind".

Accel
Accel "Accel!"

- Transformation announcement

Statistics Ability Perimeters: Like Kamen Rider Double, Ryu Terui transforms into Kamen Rider Accel through the use of USB flash drive-like objects called Gaia Memories. However, Accel only has access to a single form with which he fights through the use of the Accel Memory which he inserts into the AccelDriver. His Maximum Drive is the Accel Glanzer (アクセルグランツァー), after charging up to a point when Accel is engulfed in orange flames he executes a jumping spinning heel kick. This can be used with Kamen Rider Double FangJoker's Fang Strizer to perform the Rider Twin Maximum (ライダーツインマキシマム) finisher. While armed with the Engine Blade, Kamen Rider Accel has additional Maximum Drives.
 * Rider Height: 194cm
 * Rider Weight: 93kg
 * Punching Power: 10t
 * Kicking Power: 12t
 * Maximum Jump Height: 47m
 * Maximum Running Speed: 100m/3s
 * Accel Glanzer: 35t

Accel Yellow Signal Version
Accel Yellow Signal Version Yellow Signal Version (イエローシグナルバージョン) is a form Accel gains briefly during his transformation into Trial Form, which is similar in appearance to his main form, but being yellow in color.

Bike
The power of the Accel Memory allows Accel to change into a motorcycle-like form called Bike Form (バイクフォーム). This form is accessed by removing the Accel Driver buckle from the belt when the Face Flasher (フェイスフラッシャー) lights up. Bike form can also combine with Double's Boilder, Turbler, and Splasher units to become the AccelBoilder (Start Dash mode too), AccelTurbler, and AccelSplasher. In Kamen Rider W Forever: A to Z/The Gaia Memories of Fate, Bike Form has its own Maximum Drive after the Engine Memory is inserted in the Accel Driver and Accel switches to Bike Form. The Maximum Drive is a super-powered dash as Bike Form through the target and it is called the Bike Engine Dasher.
 * Overall Length: 2.650m
 * Width: 0.82m
 * Height: 0.98m
 * Weight: 98kg
 * Highest Speed: 920km/h

Gunner
Accel Bike Form can combine with Gunner A to become the AccelGunner (アクセルガンナー). The Accel Memory links with the Gaia Cannon (ガイアキャノン) to release energy similar to a Maximum Drive called the Gunner Full Break (ガンナーフルブレイク). It is also armed with the Gattling Wheel (ガトリングホイール), Bike Form's back wheel turned into a machine gun.

Boilder
Bike Form can also combine with RevolGarry's Boilder unit to become the AccelBoilder (アクセルボイルダー). However, this form was not shown in the series.

Turbuler
AccelTurbuler (アクセルタービュラー): Kamen Rider Accel Bike Form can combine with the RevolGarry's Turbuler unit to become the AccelTurbuler. Not only does Accel have use of the Scramble Cutter (スクランブルカッター) guns, he can also assume a humanoid form in order to execute his AccelTurbuler Phoenix (アクセルタービュラーフェニックス) Maximum Drive, where he pierces through his target while covered in flames forming the English letter A.

Splasher
Bike Form can also combine with RevolGarry's Splasher unit to become the AccelSplasher (アクセルスプラッシャー). However, this form was not shown in the series.

Trial
Accel Trial "Trial!"

- Transformation announcement

Statistics Ability Perimeters:
 * Rider Height: 197cm
 * Rider Weight: 82kg
 * Punching Power: 2.5t
 * Kicking Power: 3t
 * Maximum Jump Height: 90m
 * Maximum Running Speed: 100m/0.27s

Accel Trial (アクセルトライアル) is the first evolved form of Kamen Rider Accel. It is significantly faster than Accel's normal form, but it sports weaker armor and overall power. It is more than enough to make up for its weakness by being able to punch and kick at blinding speeds, as well as increasing his overall movement speed (running, dodging, etc.) to a great degree. Once the Maximum Drive is initiated, Accel Trial can only be used for another 10 seconds before being forcibly reverted back to human form, but the transformation is retained if the Trial Maximum Drive is successful before the 10 seconds are up. This form's Maximum Drive is the Machine Gun Spike (マシンガンスパイク), a series of multiple kicks in a row which leave a series of energy treadmarks in the form of a T, only limited by the amount of kicks Accel uses before time runs out.

While transforming from into Accel Trial, Kamen Rider Accel changes colors from red, to yellow, and then finally to blue as Accel Trial. The yellow colored form has been labeled as Kamen Rider Accel Yellow Signal Version in the toy line.

Double (W) Xtreme
Cyclone Accel  Xtreme CycloneAccelXtreme is a hypothetical form of Kamen Rider Double described by Shroud as being the ultimate form, with the change being that Ryu Terui becomes one with Philip instead of Shotaro, as their physiology make them immune to the psychological attacks of the Old and Terror Dopants. Shroud states that Ryu's hatred and rage is needed for Double to fight at its full potential. However this form was never utilized in the series as Ryu decides not to fight as part of this form while showing Shroud that they can fight with compassion rather than hatred.

Booster
Accel Booster "Accel, Upgrade: Booster!"

- Transformation announcement

Accel Booster (アクセルブースター) is a second evolved form of Kamen Rider Accel that appears in Accel's version of the Kamen Rider W Returns DVD releases. This yellow-colored form of Accel uses the Gaia Memory Enhancing Adapter stolen from the Commander Dopant, which is attached over the top of the Accel Memory to increase its power output threefold.

Accel Booster's most notable feature is its additional armoring compared to Accel Trial, which hides a plethora of jet boosters enabling Accel to fly with great mobility, leaving large contrails of fire due to the tripled thermal energy output. Like Accel's other forms, it can utilize the Engine Blade and perform the Booster Slasher (ブースタースラシャー) Maximum Drive, where the Engine Blade project a large golden energy blade to slice through the target.

Accel Booster's first appearance was in Kamen Rider W Returns: Kamen Rider Accel and reappeared in Kamen Rider × Kamen Rider Wizard & Fourze: Movie War Ultimatum. }}

Devices

 * Accel Driver: Transformation belt
 * Gaia Memories:
 * Accel Memory: Allow Ryu to become Kamen Rider Accel
 * Engine: Only use in the Engine Blade
 * Trial: Allow Accel to become Accel Trial
 * Memory Gadget
 * Beet Phone
 * Gaia Memory Enhancement Adapter: A special device that increases a Gaia Memory's power output threefold.

Weapons

 * Engine Blade: Personal weapon

Vehiles

 * Diablossa: Ryu's personal bike
 * Gunner A: Accel's personal robotic tank