Shuichi Kitaoka (北岡 秀一 Kitaoka Shūichi) is Kamen Rider Zolda (仮面ライダーゾルダ Kamen Raidā Zoruda, Masked Rider Zolda), a character in the tokusatsu production Kamen Rider Ryuki. He is the fourth of the 13 Kamen Riders the story revolves around. However, he served as the third main Rider in the series.
He is a self-proclaimed "Super-lawyer", tends to only help someone if he has something to gain. Because he has a terminal case of cancer and was given only several more months to live, Kitaoka accepted Kanzaki's offer to join the Rider war. His prize is to be immortal so that he could continue his extravagant lifestyle. Because of his illness, he suffers from frequent dizzy spells and fainting.
He first meets Shinji Kido after he clears the Sakura Company of its credit fraud charges and is later pursued by its bookies after taking their dirty money as added payment for his services. Though Shinji was unaware of this at first, he attempts to save Kitaoka only to be rescued by his apprentice Goro Yura. Shinji later meets Kitaoka again when he and Reiko wanted permission from the Kawazu Pharmacy to inspect their factory for environmental violations. Interested in Shinji, Kitaoka allows Shinji to hang around with him and understand his ideology until Shinji hit a nerve of Kitaoka's thought to live for one's own desire seemed hollow made Kitaoka kick him out.
Later, after attacking Kamen Rider Ryuki just as Ryuki kills a Zebraskull, Kitaoka learns that Shinji is in jail for suspected kidnapping and agrees to help him on the condition that Reiko writes a special article to boost his positive image. However, learning that Shinji's Ryuki with seeing the wound he inflicted in their fight, Kitaoka goes to Atori Cafe to get his pay from Ren. However, when a Wildboarder attacks, Kitaoka exposes himself while learning that Ren is a Rider - Kamen Rider Knight - as well. After fighting him, Kitaoka questions Ren's reasons for not killing Shinji. Kitaoka had intended to frame Shinji for kidnapping but after being fired as Shinji's lawyer when his intentions were revealed, Kitaoka is annoyed that Shinji is freed because of a girl named Yukari whom he brushed off while refusing to aid her. But after learning that her mother is hospitalized, Kitaoka secretly pays for her mother's surgery and earns the girl's respect. However, Zolda manages to sneak attack Ryuki and Knight while they were fighting the Wildboarder with Magnugiga, killing the monster while giving Ren memory loss in the overkill attack.
Kitaoka later gives Goro use of Zolda for a while to conceal himself, until get sets up a scheme of having Shinji believe he accidentally killed Goro to have him quit being a Rider. But his arrogance of barring ORE from a press conference to spite Reiko led to her helping Ren expose the lawyer as the real Zolda. After bailing out the son of one of his clients, Jun Shibaura, Kitaoka drops his long time client Takeshi Asakura out being tired of the man's attitude, leading Asakura receiving aid from Kanzaki. Eventually the two found out they were both Riders and they began a personal feud against each other. Though Shinji would attempt to warn him of this while under the effect of Kamen Rider Odin's Time Vent, Kitaoka faked helping Shinji and later states that fulfilling his wish to win the Rider War is more important than Asakura staying behind bars.
As the war goes on, Kitaoka becomes weaker and weaker. He begins to have doubts whether he can truly win the war. He also grows to care for Shinji, unwilling to fight him when he saw that, while Shinji requested to fight, his heart wasn't in it.
Kitaoka was the only Rider to voluntarily give up the fight rather than be killed, realizing that while his life was a short life, it was a good one. While he died in peace at his home, Goro went to fight against Ouja in his place as Zolda; Goro, not used to Zolda's long-range style, died with Asakura learning too late that he is denied taking Kitaoka's life himself. After Kanzaki restored time to its proper course after Yui's death, Kitaoka and Goro were both given a second chance at life, though it was never revealed if Kitaoka still has cancer or not.
Kamen Rider X
Kamen Rider Amazon
Kamen Rider Super-1
Kamen Rider ZX
Kamen Rider Black/RX
Kamen Rider Kuuga