Ryu Terui

Kamen Rider Accel (仮面ライダーアクセル Kamen Raidā Akuseru) is a fictional character in the 2009 – 2010 Kamen Rider Series, Kamen Rider Double, and is the series second Kamen Rider after the titlular Kamen Rider Double. The name comes from the English word "acceleration" and his motif is that of the letter A as well as a motorcycle.

Ryu Terui
Ryu Terui (照井 竜, Terui Ryū, portrayed by Minehiro Kinomoto) is a Superintendent appointed to the Futo Police Department's Paranormal Crime Investigation Division (超常犯罪捜査課, Chōjō Hanzai Sōsaka), and is Jinno and Makura's superior. Prior, Ryu lost his family when they were murdered by Isaka, driving Ryu to find the "Man with W Memory" with the aid of the mysterious Shroud while developing a hated of Futo and seeing it as a gathering place of all kinds of scum.

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, 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.

In his Rider form, Ryu tends to say "Now, let's break away!" (さあ、振り切るぜ!, Saa, furikiru ze!) 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!, Zetsubō ga omae (-tachi) no gōru da!, as Accel) 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！, [0.1-9.9]-byō, sore ga omae no zetsubō made no taimu' da!, as Accel Trial) 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.

Accel Driver
The Accel Driver (アクセルドライバーAkuseru Doraibā) is Kamen Rider Accel's transformation belt. It is a third generation Memory Driver given to Ryu Terui by the mysterious woman known only as "Shroud". The AccelDriver resembles a set of motorcycle handlebars. By inserting the Accel Memory into the Mono Slot (モノスロット Mono Surotto) and revving the Power Throttle (パワースロットル Pawā Surottoru) on the right handlebar, Ryu Terui transforms into Kamen Rider Accel. By squeezing the Maximum Clutch Lever (マキシマムクラッチレバーMakishimamu Kuratchi Rebā) on the left handlebar and revving the Power Throttle, Kamen Rider Accel initiates his Maximum Drive (マキシマムドライブ Makishimamu Doraibu) finisher attack.

Gaia Memories
Like Kamen Rider Double, Kamen Rider Accel possesses his own set of Gaia Memories (ガイアメモリ Gaia Memori).
 * Accel Memory (アクセルメモリ Akuseru Memori): The Accel Memory, or Acceleration Memory (加速の記憶Kasoku no Kioku), is Kamen Rider Accel's primary GaiaMemory. This enables Terui to transform into Kamen Rider Accel and access his primary Maximum Drive, as well as allow him to assume Bike Form.
 * Engine Memory (エンジンメモリ Enjin Memori): The Engine Memory is a Gaia Memory that gives the EngineBlade its various different powers. It is not a true Gaia Memory however, and its powers are linked to the Accel Memory. This allows the Engine Blade to have three different elemental abilities imbued in it, each based on a different type of engine: Jet (ジェット Jetto) which allows the Engine Blade to fire jet blades or a blade energy wave, Electric (エレクトリック Erekutorikku) which allows the Engine Blade to do high powered electric slash, and Steam (スチーム Suchīmu) which creates a wave or wall of steam.
 * Cyclone Memory (サイクロンメモリ, Saikuron Memori): Ryu is briefly lent Philip's Cyclone Memory to battle the Weather Dopant. When inserted into the Engine Blade, it allows Kamen Rider Accel to perform a wind-powered Maximum Drive.

Trial Memory
The Maximum Counter Trial Memory (マキシマムカウンタートライアルメモリ, Makishimamu Kauntā Toraiaru Memori), also known as the Challenge Memory (挑戦の記憶, Chōsen no Kioku), is a special Gaia Memory that allows Kamen Rider Accel to become Kamen Rider Accel Trial. While in Memory Mode (メモリモード, Memori Mōdo), the Trial Memory enables Accel to transform; the transformation is complete once the light on the traffic light-like Trans-Signal (トランスシグナル, Toransu Shigunaru) goes from red to blue (with a 3-second countdown sound effect). While in its stop watch-like Maximum Mode (マキシマムモード, Makishimamu Mōdo), once the Maximum Switch (マキシマムスイッチ, Makishimamu Suitchi?) timer button is pressed, Accel Trial has 10 seconds to perform as many kicks as possible before pressing the Maximum Switch again to activate the Maximum Drive. If the Maximum Switch is not pressed within 10 seconds, the Maximum Drive fails and Accel's transformation is forcibly and painfully reverted. To handle this, Accel normally tosses the Trial Memory into the air as the Maximum Drive begins, pressing the Maximum Switch as soon as it is caught and declaring the time received.

Engine Blade
The Engine Blade (エンジンブレード Enjin Burēdo) is Kamen Rider Accel's main weapon. The weapon can be wielded outside of Accel's transformation, though it is extremely heavy. Through the use of the Engine Memory, Kamen Rider Accel can perform different elemental powers by pulling the trigger. It also allows Accel to perform two unique Maximum Drive finishers with the Engine Blade. The first is the Dynamic Ace (ダイナミックエース, Dainamikku Ēsu) in which a concentration of energy in the shape of the letter A is sent out from the EngineBlade. The second is called the A-Slasher (エースラッシャー, Ē Surasshā) where Kamen Rider Accel performs three consecutive slashes that form the letter A in a horizontal or vertical plane, slashing through the Dopant to destroy it. The Engine Blade can be used with any of Double's Memories for a Maximum Drive. As Kamen Accel Trial, he is able to perform a variation of his Machine Gun Spike Maximum Drive by using the Trial Memory in combination with the Engine Blade's Maximum Drive. When Accel Trial combines the Engine Maximum Drive with the Trial Maximum Drive, he can perform the Machine Gun Slasher (マシンガンスラッシャー, Mashingan Surasshā) Maximum Drive, repeatedly slashing the target in the time limit rather than kicking.

Gaia Memory Enhancement Adapter
The Gaia Memory Enhancing Adapter (ガイアメモリ強化アダプター, Gaia Memori Kyōka Adaputā?) is a special device that increases a Gaia Memory's power output threefold. It was also used by the Commander Dopant before it was taken by Aoi Katsuragi who gives it to Kamen Rider Accel to become Kamen Rider Accel Booster. The Gaia Memory Enhancing Adapter was used on the Unicorn Memory by a yakuza leader, however the Memory was destroyed by Ryu before it can be used.

Memory Gadget
Like Double, Kamen Rider Accel has his own Memory Gadget (メモリガジェット Memori Gajetto), an item powered by an artificial Gaia Memory called a Giji Memory (ギジメモリ Giji Memori, "Pseudo Memory") that allows it to switch between its Gadget Mode (ガジェットモード Gajetto Mōdo) and its Live Mode (ライブモード Raibu Mōdo).
 * The Beetle Phone (ビートルフォンBītoru Fon) is a mobile phone that switches between Cell Phone Mode (携帯モード Keitai Mōdo) and Beetle Mode (ビートルモード Bītoru Mōdo) with the use of the Beetle Memory (ビートルメモリ Bītoru Memori). It looks similar to the Stag Phone, except it has a blue Japanese rhinoceros beetle design. Prior to its appearance in the series, Ryu Terui used the Beetle Phone to spy on the Narumi Detective Agency.

Diablossa
The Diablossa (ディアブロッサ, Diaburossa) is Kamen Rider Accel's personal Ducati 999 motorcycle. It also has a holder for the EngineBlade. Its name comes from the Italian words "Diabolo" (devil) and "Rosso" (red); fitting, as Ducati is an Italian company.[6]

Gunner A
The Revol-Interchange Gunner A (リボル換装 ガンナーA, Riboru Kansō Gannā Ē) is a robotic tank that serves as Kamen Rider Accel's support droid. Its AI allows it to operate on its own from Accel. The technology is similar to Kamen Rider Double's HardBoilder and the front unit can also combine with the Gunner A to become the HardGunner (ハードガンナー, HādoGannā).

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

Accel Turbuler
Accel Bike Form, in battle against Ryubee Sonozaki's Terror Dragon, combined with the RevolGarry's Turbuler unit to form and fight as the '''AccelTurbuler. '''