Shotaro Hidari

"Kamen Riders are this city's symbol of hope!"

- Shotaro, rejecting Eternal's claims to be a Kamen Rider

Shotaro Hidari (左 翔太郎) is the left hand side of Kamen Rider Double (仮面ライダーダブル), but also a Rider in his own right as Kamen Rider Joker (仮面ライダージョーカー). A self-proclaimed "hardboiled detective", he dresses in a retro fashion based on late-1930s style, favoring fedora hats and waistcoats. He is often called 'half-boiled' by his friends, however, because he cannot fully shut out his doubts, was initially seen as inexperienced, often acts according to his feelings, and has difficulties making cruel yet necessary decisions, contrary to his hard-boiled aspirations. He later on becomes more respected though, as he proved himself throughout the series. He works as a private detective in the city of Futo.

History
Vowing to stop anyone that makes his city cry after, as a child, witnessing Sokichi Narumi's first fight with the Spider Dopant, Shotaro eventually became Sokichi's protégé. His final job with Sokichi involved investigating a mysterious organization, at the behest of an equally mysterious client. While infiltrating a Gaia Memory research building, Shotaro met Philip for the first time. However, due to Shotaro's recklessness, their cover was blown and it indirectly led to Sokichi being shot to death. Sokichi then left Shotaro to continue on in his stead, giving Shotaro his prized fedora in his final moments. Shortly afterwards, Philip and Shotaro used the Double Driver - which Sokichi had been carrying, perhaps with the intent that he become the body of W - to transform for the first time, in order to escape.

Refusing to let his mentor's memory be in vain, and to atone for his mistake, Shotaro works to stop the Dopant crime wave by being the man on the street, contacting his various informants and transforming into Kamen Rider Double by providing his body for the combination. Shotaro also appears to be the one who came up with the names of Double's finishers, as demonstrated in episode 16 when he decided to call FangJoker's Maximum Drive "Fang Streiser". Though this is ostensibly to enable him and Philip to synchronize themselves better, it seems Shotaro simply likes doing it, as he names his attacks when he fights solo as well.

Shotaro's physiology was not ideal for Gaia Memory use, and he was never Shroud's ideal choice for the 'body' half of W. Because of this, he had trouble maintaining their Rider form when Philip's power was evolving. However, he later proves that he has a knack for being the 'wild card', being incredibly difficult to predict in such a manner - this quality leads not only to him resonating strongly with the Joker Memory and match Philip's heightened power, but also displaying the ability to exceed expectations and being able to transform into Kamen Rider Double CycloneJokerXtreme by sheer willpower. In fact, he later on manages to transform into CycloneJokerGoldXtreme showing how accustomed he became with Gaia Memories as Kamen Rider W. After defeating Museum and the Utopia Dopant, Shotaro had to part with Philip for a year while stopping Dopants as Kamen Rider Joker. Eventually after a series of events, Shotaro and the others reunite with Philip as they transform into W once more.

Kamen Rider Taisen
Shotaro returns in Kamen Rider Taisen, as both Kamen Rider Double and Kamen Rider Joker. After being informed what happened in Japan, Shotaro meet with Tsukasa and Kaito, to be asked for finding someone related to Shun Aoi but refuse it due receiving job to search the missing pets (which Kaito claims to be idiotic). After being helped by Kaito, Tsukasa tells about the Heisei and Showa Riders are beginning to fight and he wants Shotaro to research the reason as it is related to Shun. Soon, he confronts by two BLACKs who think that Heisei Riders are nuisances as they attack Tsukasa when he is taking Shun to his mother. Shotaro tells Tsukasa to leave it to him as he hold off the two BLACKs as Kamen Rider Joker. Katio soon helps him as Kamen Rider Baron. In the battle, with the Kaito's help, he defeats Black RX with Rider Kick.

At the climax, Joker is one of the surviving Riders in the battle between Heisei and Showa. He faces Kamen Rider Black, with the two Riders taking each other out with their Rider Kicks. Gaim is soon left as the last Rider standing before Ambassador Darkness of the Badan Empire reveals himself to be Ryo Murasame (Kamen Rider ZX). He, alongside all 30 Kamen Riders are restored to defeat the Badan Empire.

In the final battle, he fights 2 and stopped after 1 proclaims his loss against Gaim. In the alternate ending to this movie, he stopped fighting after 1 proclaims his victory against Gaim. Nonetheless in the ending credits, Shotaro continued his search for a missing cat.

Kamen Rider Travelers Record
Aside from Kamen Rider Double, Shotaro appears transforming into Kamen Rider Joker in the video game Kamen Rider Travelers Record.

Personality
Shotaro's basic personality is an homage to the fictional detective Philip Marlowe (ironically, his partner's namesake), as is his aspiration to be a hard-boiled detective. Shotaro's decisiveness and honed detective intuition make him a remarkable detective even without the help of his partner. However, his friends and contacts often refer to him as 'half-boiled', as he was (initially) thought to be inexperienced (until Movie War 2010 where the A.R Narumi Soukichi accepts him as a full fledged detective) by others along with the fact that he wears his heart on his sleeve and lets his emotions get in the way of making the cruel yet necessary decisions that real hard-boiled detectives, such as his mentor, would have little problem making. He also felt guilty for Sokichi`s death and felt unworthy of wearing his hat. Eventually after a series of events including meeting the A.R Sokichi and defeating Museum did Shotaro feel worthy of wearing his mentor`s hat as he faced the Utopia Dopant. Even though his emotion and dedication to the choices that he makes causes him to come to blows with his partner and others, there is an affection to their calling him 'half-boiled', and eventually he accepts it as his way of doing things. Despite his flighty exterior Shotaro cares deeply about his clients, his friends, and his city and will do anything in his power to protect them. This is shown when he manages to overcome the Terror Dopant`s maddening effects despite not having the same immunity as Philip or Ryu. While he doesn`t seem to forgive those who would make Futo and it`s citizens cry, he does not seem to hold a grudge against people but rather the crimes itself.

Shotaro is a contrast to his partner Philip, showing great capacity for emotion and empathy as opposed to Philip's cold and logical thinking. Because of his emotional side, he is capable of understanding the emotions and actions of others. It is continual exposure to Shotaro's emotional nature that leads to Philip warming up to his own emotions. Despite being referred as inferior to Sokichi by some, Shotaro has some remarkable traits that Sokichi didn`t have, a great example being his merciful side as he tries to save lowly criminals, unlike Sokichi who ruthlessly allowed the Bat Dopant to die. Due to his aspiration to be hard-boiled, Shotaro usually tries to be the serious and cool-looking one in his group, but that often results in him often being the one who is being made a fool of by others, his friends and enemies alike. Shotaro takes the role of Kamen Rider Double very seriously and with great pride, as the name "Kamen Rider" was given to them by the citizens of the city themselves. As such, he tries very hard to make a good name for Kamen Rider Double, and live up to expectations that came with the title.

He is fond of anything retro and this can seen from what he wears to he uses. He is rarely seen wearing anything that is not a set consisting of a dress shirt, a pair slacks, a necktie, a waistcoat and most importantly (to him at least), a fedora hat. He is always seen typing on a typewriter for case-filing purposes, despite having a laptop in the hangar. His bike helmet is also a retro-styled one. His fondness for retro-styled items is so intense that one can say that his use of anything modern is only out of necessity.

Shotaro has a habit of flicking his left wrist in the air before and during battles, similar to Takumi Inui's habit of flicking his right wrist at his side after transformation.

Abilities
Being trained by Sokichi for years, he has honed his detective skills enough to become a competent private detective who is able to solve cases even without the help of Philip. He has a keen eye for details and has good deductive intuition, as such he is able to piece information together quickly and coherently and thus rarely fails in determining the culprit behind cases. His skills is such that the police, specifically Ryu, would often come looking for his help when dealing with Dopant cases.

Oddly enough, he has also shown a great skill in locating pets easily, more so than finding people, first seen when trying to locate a cat not knowing it was a trick and finding Mick. As a result, he has developed a fame out of it and most of his clients sought him out so to locate their lost pets, to his chagrin.

In combat, Shotaro proves himself to be a competent fighter even without using Gaia Memories, being able to take on several Masquerade Dopants without having to transform. Even in a weakened state of becoming an old man due to the Old Dopant, he is still able to make use of whatever motor skills and stamina left in his deteriorated body to put up a good fight. He is also quite adept at teamwork as frequently shown when he fights as W.

Kamen Rider Joker
"Joker! (Orchestral hit)"

- Transformation announcement

Ability Perimeters: Through the power of the T2 Joker Memory and the Lost Driver, Shotaro uses the power of the Joker Memory to its full potential. When the Memory is placed into the Maximum Slot, Joker executes either a Rider Punch or Rider Kick Maximum Drive. Along with Kamen Rider Cyclone, the two can execute Double Rider Kick Maximum Drive. This form is lost after the fight with NEVER; But, after Philip dissolves into data and becomes one with the Earth, Shotaro finds in the present Philip gave to him, the Lost Driver from the incident. He uses his original Joker Memory in place of the T2 Joker memory to become Kamen Rider Joker again. However, one year later, Shotaro is overwhelmed by the newly formed EXE group until Philip returns. It is shown in Movie War Mega Max, that if he finds Philip is in the middle of one of his obsessions again and too occupied to fight, he will swap out the Double Driver for the Lost Driver. While only statistically half as strong as W`s CycloneJoker form, since Shotaro can fight on his own, this form may actually be more powerful in it`s own way. This is somewhat hinted when he held his own against Eternal despite quickly being overpowered by him in their last encounter as W FangJoker and CycloneJokerXtreme Forms.
 * Height: 195 cm.
 * Weight: 85 kg.
 * Punching Power: 1.25 tons
 * Kicking Power: 3 tons
 * Maximum Jump Height: 30 m
 * Maximum Running Speed: 100 m. per 6.2 sec

Devices

 * Double
 * Double Driver - Transformation belt as Double
 * Gaia Memories - Devices that are used in Double's transformation or power-ups in finisher attacks.
 * Xtreme Memory - a bird-themed Gaia Memory that further empowers Double.
 * Memory Gadgets - Support robots that are empowered by pseudo-Gaia Memories.
 * Joker
 * Lost Driver - Transformation belt as Joker, received from the spirit of Sokichi Narumi, lost in the battle against Eternal but later gained another from Philip.
 * Gaia Memories- Devices that are used in Double's transformation, Shotaro uses the Joker memory in this form.
 * T2 Gaia Memories - Latest model of Gaia Memories, Shotaro used one, the Joker Memory which was later destroyed alongside the other T2 Gaia Memories..

Weapons

 * Double
 * Maximum Slots - Gaia Memory slot that enables Double to perform Maximum Drive as barehanded.
 * Metal Shaft - Extendable quarter staff in conjunction with any form that uses the Metal Memory.
 * Trigger Magnum - Firearm in conjunction with any form that uses the Trigger Memory.
 * Prism Bicker - A pair of sword and shield that used in Extreme Modes.
 * Joker
 * Maximum Slots - Gaia Memory slot that enables Joker to perform Maximum Drive as barehanded.

Vehicles

 * HardBoilder - Double/Joker/Shotaro's main Rider Machine.
 * RevolGarry - Double's main base of operation and truck which supply power-ups for HardBoilder.
 * HardMammother - Temporary elephant mecha stolen from Super Shocker. Destroyed after used as a suicide attack.
 * Gunner A - Accel's mecha/robot ally, borrowed by Double in a battle against a Quetzalcoatlus Dopant.

Portrayal
Shotaro Hidari is portrayed by Renn Kiriyama (桐山 漣). As a child, Shotaro is portrayed by Issei Kakazu (嘉数 一星). Kakazu later portrays Akira Aoyama in the television series' final episode. As an elder in episodes 43 and 44, Shotaro is portrayed by Yukimasa Natori (名取 幸政).

As Kamen Rider Double (and Kamen Rider Joker), his suit actor was Seiji Takaiwa (高岩 成二), who has been the suit actor for the majority of leading Heisei Kamen Riders (except Kuuga and Hibiki).