|This article is about a/an character in Kamen Rider OOO and Kamen Rider Den-O.|
Mitsuru (ミツル Mitsuru) is one of the children who was hiding from Shocker armies due to Ankh's mistake in November 11, 1971.
After Ankh accidentally dropped one of his Cell Medal in November 11, 1971, it causes time paradox which made the Shocker armies to finally achieve their plan to invade the whole Japan. Mitsuru's parents were among the scientists who were kidnapped to become their workers. On April 1, 2011, after Ankh and Eiji return from the past through DenLiner, Mitsuru and Naoki stole some Ankh's Core Medal Case and ran away as Ankh and Eiji chase them to their hideout as the kids passed their Core Medal to the other children. However, the whole thing was interrupted by the police, who were revealed to be Shocker soldiers. When Shigeru was caught by the police, Eiji rushes in and transformed into Kamen Rider OOO to battle them, which shocked the children because they grew up believing that Kamen Riders were the elite soldiers of Shocker. OOO gained the upper hand but was soon weakened after Kamen Rider 1 and Kamen Rider 2 arrived, which confused Eiji more. After lamenting on how a Kamen Rider helped them and seeing Eiji differently from the Riders they knew, the children returned the Core Medal Case to OOO, allowing him to use the Lartoratar Combo's head flash and super speed to retreat. On their way, they were ambushed by General Shadow, which caused OOO's to revert to Eiji. They were about to be killed when the Denliner crew arrives to pick them as they reveal to Eiji that the whole problem occurred due to the time paradox which was caused by Ankh after he accidentally drop it.
Eiji and Shigeru - one of the children - are dropped back to the slum area, while both Naoki and Mitsuru stayed hidden aboard the DenLiner. Ankh was also seen hidden on the train, he was then caught by Owner with a chain and have Momotaros to keep an eye on him. Although the Cell Medal was successfully destroyed a fight occurred which caused four more Cell Medals to be thrown out from Ankh's hand. As three of four Cell Medals were destroyed by the Taros, one was found by Nokko as she mistakes all of them as Shocker agents and contacts the Kamen Rider Scouts. Mitsuru and Naoki intercepted her and after some talk which should have cleared all the confusion, Ankh became impatient and caused another commotion which led to the Medal being picked by a Shocker Soldier and gave it to Black Shogun. Naoki, Mitsuru and Nokko recovered the Medal and escaped into a warehouse, but were surrounded by Shocker soldiers before the Double Riders appear and intervene - destroying the army's two Kaijin commanders with their Rider Kicks. The Double Riders and the children trick Black Shogun into taking a fake Medal with a transmitter so they can locate Shocker's headquarters. Before they proceed, New Den-O destroys the real Cell Medal to prevent any further trouble. However, as they tracked the Shocker agent to their base, General Black revealed to them that the one New Den-O had destroyed was also a fake Medal and the real one remains intact in his hand. He released the Cell Medal and the Great Leader of Shocker combines it with the Shocker Core Medal that they have created, which resulted in the birth of the Shocker Greed. Owner orders everyone to retreat as the Turtle Bazooka attacks the train. Still wanting to help the past riders, Naoki jumps off the DenLiner followed by Teddy and promised that he will to protect Naoki.
Returning to the present, Mitsuru saw the DenLiner explode and the two Riders being caught. Escaping to their second hideout, the children discovered Macheteddy's corpse and a time capsule containing Kamen Rider Scout uniforms and a letter from Naoki, telling them that after the Shocker Greeed defeated the Double Riders, he and the Scouts became fugitives while Teddy died protecting them reverting him back in his Macheteddy form. Surrounded by Shocker armies, Hina and the children ran away along with the OOO Driver as Momotaros used Shingo's body as host so that he could buy them some time. Attending the Riders' public execution, inheriting the will of the Kamen Rider Scouts, the kids wore the Scouts' uniforms and interrupted the ceremony in an attempt to give Eiji the OOO Driver, although it was quickly apprehended before the Double Riders arrived and revealed that they were no longer brainwashed. This makes the crowd scramble and revolt against the Shocker armies as they unchained the Riders. In the end, Teddy plans to bring Naoki back to the present, only to be interrupted by a middle-aged man who was revealed to be Mitsuru's father. Upon seeing the scar on the scientist's hand, it was revealed that he was also Naoki and that Nokko was Mitsuru's mother. He also revealed that he allowed himself to be captured in order to foil Shocker's plan by undoing the Double Riders' brainwashing.