|“||Everyone bow before me!||„|
|~ Yuko Kitajima|
In 2015, Yuko was jailed after beating the girlfriend of her ex-boyfriend to death with a manhole cover. The event was witnessed by Geiz when he traveled back to the night of the murder to see what really happened.
After spending years inside prison, Yuko was visited the Time Jacker Ora and received the Kiva Anotherwatch from her. Yuko used the Anotherwatch to become Another Kiva and with her new Another Rider powers broke out of prison. After getting several treatments to restore her beauty, Yuko set out to become the "Queen of the World" to right the laws which had led to her being wrongfully locked up for years. Her first act was to target those who were responsible for imprisoning her, attacking the lawyers who had gotten her convicted.
Yuko's attacks soon attracted the attention of Sougo Tokiwa, who became Kamen Rider Zi-O to fight her, but Another Kiva managed to fight him off, knocking him out of his transformation. As Sougo lay up beside a wall, Yuko went up to him and told him he was a "cute kid", causing Sougo to mistakenly identify her as his first love, a girl who had played with him at a playground once.
Later, when Ora confronted her and tried to control her, Yuko declared that Ora was her subject and flung a manhole cover at for refusing to submit to her, scarring her face much to the amusement of Sworz and Uhr.
When Zi-O, Geiz and Woz went to confront her again, their face off was interrupted when Kamen Rider Ginga arrived on Earth and blasted Another Kiva after she tried to command him, proclaiming that as a being from space he was not susceptible to Earth's laws.
Sougo and co. and the Time Jackers later attempted to convince her to ally to defeat Ginga, but Yuko demanded they all bow before her first. When they did this though Yuko stated that she had changed her mind about Ginga and would simply ignore him before walking off.
While Sougo and Woz dealt with Ginga and Another Kiva, Geiz traveled to 2015 to the night Yuko allegedly killed someone to discover what really happened that night and if Yuko's claims of being wrongfully convicted were true. To his shock, he saw Yuko indeed was guilty of murder and traveled back to 2019 to warn Sougo.
Yuko later crashed the wedding of her ex-boyfriend, transforming into Another Kiva and sending her Arms Monsters to assault the wedding guests. She was then confronted by Zi-O and Kamen Rider Woz, but Zi-O found he could not bring himself to finish off Yuko, leaving Woz to defeat her. Another Kiva was evnetually defeated by Kamen Rider Woz Ginga Finally and knocked out of her transformation. As Sougo held her in his arms, Yuko told him to be an umbrella to the whole instead of her. It was then Ora took the chance to kill Yuko as revenge for her previous mistreatment of her, leaving her to die in Sougo's arms.
Yuko is a very vengeful person. One of her first acts upon receiving her powers was to assault her own lawyer in her murder case, blaming him for her being locked up. She is incredibly narcissistic and enjoys making people bow to her. Even though she received her Another Ridewatch from the Time Jackers she refuses to submit to them and sees Ora as her servant. Yuko is also incredibly manipulative, willing to play on Sougo's love for her in order to control him into doing what she wants.