Takeshi Asakura

Kamen Rider Ouja (仮面ライダー王蛇 Kamen Raidā Ōja) is a Rider in the Kamen Rider Series Kamen Rider Ryuki. He is the sixth of the 13 Kamen Riders the story revolves around. His true identity is Takeshi Asakura.

By default, Kamen Rider Ouja is a melee-based Rider. The fighting style of his alter ego, helped him in his victories more often than any of his Advent cards, although more than anything else, he used his Sword Vent card to summon a spiral sword. Once Ouja defeated Kamen Riders Gai and Raia, he had access to both their contract monsters and their Advent cards, turning the already homicidal Ouja into an even more dangerous force to be reckoned with.

Series
At age 13, Takeshi Asakura (浅倉 威, Asakura Takeshi), murdered his entire family in a fire, though his younger brother survived. Since, Asakura developed a reputation as a sadistic felon with a love to fight, maim and otherwise destroy anything, in his random fits of rage. As a result of his sadistic nature, prior to becoming a Rider, Asakura was personally responsible for both the piano career of Tezuka's friend Yuichi Saito and murdering the older sister of Miho Kirishima. Eventually, his arrogant personality results with his defense attorney, Shuichi Kitaoka refusing to represent him and left him to rot in jail. Because he was in prison and could not feed his destructive nature, Takeshi gladly accepted Kanzaki's offer to join the Rider War and forms a pact with Venosnaker, using his new found powers as Ouja in its many forms to break out of jail, avoid the law, and get his revenge on Kitaoka.

Ouja fought only to fight and was the first Rider to actually kill other Riders, killing Kamen Rider Gai and Kamen Rider Raia and taking their Contract Monster afterwards. Ouja also destroyed Kamen Rider Imperer's deck, causing him to die in the Mirror World. While the other Riders had a desire that would be granted if they won the Rider War, Asakura was simply having fun, and said that if he won, he would wish for the Rider War to start over so he could keep enjoying himself.

Ren helped Asakura fake his death once so he can fight in the Rider War without police interference. But when he was publicly revealed to be alive, Asakura was soon later captured, going in and out of jail for several instances. In one such case, he uses Metalgelas while in a police van to dispose of his police captors before escaping into the Mirror World. After a fight with Kamen Rider Survive Ryuki and Kamen Rider Tiger, he had been seriously injured and handed back to the authorities once again by Shinji. Soon he escaped again, with aid of his lawyer at that time whom he had knocked out and switched clothes with the lawyer to escape.

In the process of learning of Kitaoka's identity as a Rider, Asakura attempted to lure him by staging a hostage situation to get Kitaoka. Asakura had Venosnaker kidnap Goro Yura so Ouja can pressure Zolda into bringing Knight, Ryuki and Raia to a specific meeting place. However, Goro escapes by picking the lock of the handcuffs. Though he lost to Zolda, Ouja survived and senselessly killed Kamen Rider Gai in the process.

Upon learning of Kitaoka's identity as a Rider, he formed a personal grudge against him that manifested in many attempts to harm Kitaoka. The two would fight many times throughout the series. Miyuki Tezuka (Kamen Rider Raia) also held a personal grudge against Asakura for ending the piano career of his friend, Yuichi Saito.

During the series, he came under fire from his three monsters when they were hungry for life energy. They came close to devouring Asakura if not for his strong determination. After hunting down three Mirror Monsters, Ouja was able to feed his contract monsters. Kamen Rider Knight and Zolda tried to prevent his monsters from feeding so that they would turn on him and remove Asakura from the Rider War. but Kamen Rider Ryuki intervened and allowed the monsters to feed because Asakura had actually saved a small girl from the three monsters they hunted.

At the end of the series he finally has his showdown with Zolda. Ouja, using his "Doomsday" Final Vent, destroys Magnugiga before fatally injuring Zolda. Though happy with his victory, Ouja finds out seconds later that "Zolda" was actually Goro, as Kitaoka gave him his vent deck prior to succumbing to his cancer during the fight. Just as he returned to the real world in utter disarray of being denied the right to kill the man he hated the most, Asakura finds himself surrounded by the authorities in the warehouse he was in with snipers covering them. Defiant to the end, Asakura grabs a metal rod and runs at the cops screaming as they gun him down, brought to justice at last.

But because Kanzaki restored time to its proper course after Yui's death, Asakura was given a second chance in life with no memory of being a Rider and keeping a low profile, but still having a rude personality, as he was kicking Shinji's bike because it was in the way.

Kamen Rider Ryuki: Episode Final
In the movie, Episode Final, Asakura was targeted by Miho Kirishima, who became Kamen Rider Femme to hunt him down for revenge. Though she was outmatched by the stronger opponent, Kamen Rider Ryuga's destroying of Genocider reverted Ouja to Blank Form. Weakened, Femme stabbed right at Ohja's blank deck, destroying it. Shortly, Ouja's armor disintegrated and Asakura dissolved in the Mirror World as he attempted to take Miho down with him.

13 Riders
In the 13 Riders Special, Asakura was already a Rider and in jail until Venosnaker busted its master out. He later kills Kamen Rider Scissors. He reappears at the end where he activates Final Vent together with the others in one ending, but he was destroyed alongside Femme & Zolda thanks to Kamen Rider Survive Knight, who broke the mirror causing him to die like his 2 remaing comrades Gai, & Scissors.

Kamen Rider Decade
In Kamen Rider Decade, Ouja is summoned in the World of Hibiki by Kiva-la, wielding a kanabō which he uses to summon a Bakegani from the mountain side after knocking Kiva-la aside.

Kamen Rider Decade: All Riders vs. Dai-Shocker
Asakura later appears in All Riders VS Dai-Shocker to fight the organization. However due to his sadistic nature he sides with with Dai-Shocker along with Kickhopper (Yaguruma). He attemps to stop Diend and Natsumi only for Diend to summon Gai, Raia, and PunchHopper to fight him and Yaguruma. He fought Gai and Raia the two riders he killed in the series. The outcome of the fight is unknown.

Fighting Style
Ouja is a melee based Rider like majority of the Kamen Riders. However, he is extremely sadistic, showing no mercy as well as superior tactics over his opponents. He fights relentlessly, but only if he is sure he will win, and isn't hesitant to use other Riders as factors or pawns in his battles. His Sword Vent is his most frequently used weapon. He becomes even more powerful when he forms Contracts with Metalgelas and Evildiver. This allows him access to Gai's Strike Vent and Raia's Swing Vent, making him a more versatile as well as a more deadly force. His Contract Monster Venosnaker participates in his battles, and is often seen as Dragredder's evil equivalent in the series (this has been replaced by Dragblacker).

However, Ouja is not without weaknesses. He's more vulnerable towards long-ranged opponents, his own unstable nature outclasses his fighting potential, he rarely uses his special card Steal Vent (possibly because he is comfortable with his choice of weapon, as well as only using it to disarm Riders, which is an ineffective strategy), and he rarely takes advantage of the more powerful Genocider, using the united Contract Monster as a more menacing or intimidating distraction in the battlefield. This may also prove that the united Contract Monster is difficult to control, but is restrainable.

Contract Monsters
See Venosnaker 

See Genocider 

Advent Cards
Kamen Rider Ouja had the most Advent Cards out of any of the Riders. This was because he obtained two extra sets of cards by contracting with two of the Mirror world monsters that were previously contracted with Riders he defeated.

Metalgelas-Based

 * Advent (AP: 4000): Summons Metalgelas.
 * Strike Vent (AP: 2000): Conjures Metal Horn.
 * Final Vent (AP: 5000): Executes Heavy Pressure. Ouja rides on Metalgelas with the Metal Horn extended in front of him to pierce through the opponent.

Evildiver-Based

 * Advent (AP: 4000): Summons Evildiver.
 * Swing Vent (AP: 2000): Conjures Evil Whip.
 * Final Vent (AP: 5000): Executes Hide Venom. Ouja rides on Evildiver's back and rams the enemy.

Genocider-Based

 * Advent: Summons Genocider.
 * Unite Vent: Combines Venosnaker, Metalgelas, and Evildiver into Genocider.
 * Final Vent (AP: 8000): Executes Doomsday. Ouja corkscrew kicks his opponent into a vortex that materializes on Genocider's torso.

Name
The name "Ouja" (王蛇, Ōja) literally translates as "King Snake", but it is used as a word for boa constrictor. Ouja's name is variably written as "Oja", "Ohja", and "Ohjya" in media released by TV Asahi, Toei Company, and Bandai. Asakura translates to 'Morning Storehouse.' It is the name of a former village, a city, and a district in Japan, as well as that of a daimyō clan.