Mirror World

The is a existing on a different in which only the Kamen Riders can safely exist and is home to the Mirror Monsters. Evidently, this spacetime exists across the multiverse, with its properties differing in each world.
==Functionality==
The real form of the Mirror World is a spacetime existing on a different dimensional plane based on , , and , thus making the real world experience . The appearance of the Mirror World is a left-right mirror-flipped "ghost town" copy of the real world, devoid of people and with all text reading backwards. It is accessed through any reflective surface, usually mirrors or windows. Ominous noises can be heard within the gateway of this dimension. Only Mirror Monsters or those possessing an Advent Deck can enter or leave the Mirror World, though the ability to see into it without a Deck is inconsistently portrayed (though Monsters in the real world are always visible). At least Blank Riders without Contract Monsters can only leave through the same reflective surface they entered through. Access through a mirror can be blocked by breaking or covering the surface, even with only newspaper, so long as it is in contact with the mirror.
In Kamen Rider Ryuki, living things not from the Mirror World cannot exist for long inside it: any person dragged into the world by a Monster will quickly be disintegrated simply by being there, and Kamen Rider armor only delays this process for a brief time, many Rider battles being cut short by this "time limit". Though unaddressed, Mirror Monsters may face a similar danger if they stay in the real world for too long. However, the Mirror World as portrayed in Kamen Rider Zi-O is confirmed to be lacking this hazardous element.The Mirror World in ZI-O is not equal to the one in TV series Ryuki but close to that in the Ryuki movie "Episode Final", where the-other-side-Shinji aka Ryuga lived. - Shinichiro Shirakura's tweet
Also in Kamen Rider Zi-O, it is possible to make contact with the Mirror World by breaking a mirror, although, perhaps by chance, only once every 1000 or so times. 
==History==
===Kamen Rider Ryuki===
The Mirror World is an alternate reality that was subconsciously created by Shiro and Yui Kanzaki in their childhood仮面ライダー龍騎超全集　最終巻 (Kamen Rider Ryuki Complete Manual, Final Volume) pg. 56, so as to cope with the abuse recieved by their parents. When Yui died from sickness, a mirror version of her entered the real world and absorbed into her, causing all windows in the mansion to shatter; Yui's double would live her life, forgetting this event, until her 20th birthday, when she would die. Drawings of monsters they had made also somehow became the Mirror Monsters. When Shiro was adopted by American relatives, he began studying and experimenting until he designed the Advent Decks to allow transformation into Kamen Riders and passage into the Mirror World. The 13 Riders would contract with a Mirror Monster to use their power and fight other Monsters and Riders, until only one remained, whereupon they would receive any one wish, though from an unclear source, which Shiro intended to use to keep Yui alive by winning with an unbeatable puppet Rider.
Hideyuki Kagawa and his associates believed that killing Yui would close the Mirror World, or at least force Shiro to do so.
After Yui faded and Ren Akiyama won the Rider Fight, Yui's reflection convinces Shiro to fix things, and seemingly through willpower alone their past is somehow altered so that they drew happy scenes as children instead of monsters, and the entirety of the events following were undone, leaving the state of the Mirror World unclear.
===Kamen Rider Ryuki: Episode Final===
In an alternate ending, the Mirror World had a slightly different history.
When child Shinji Kido was unable to meet up with Yui for a playdate due to rain, she was drawn into the Mirror World by her mirror version and played, but was told she couldn't return; her mirror self gave her life to let Yui return, but it would only last until she was 20. Shiro would develop the same methods, using the Rider Fight to select the strongest life that he could give to Yui to keep her alive past the limit. One such Rider would be the mirror version of Shinji. After Yui ended her life to convince Shiro his efforts were a mistake, he faded from grief.
It remained unaffected by the end of the movie.
===Kamen Rider Ryuki Special: 13 Riders===
In an alternate timeline, the Mirror World had a very different history that did not directly mention Yui.
With unstated origins, the Mirror World contained the Core Mirror that used drawings of monsters, also of unstated origins, to create Mirror Monsters. If the Core Mirror is destroyed, the Mirror World will close. Though people can be dragged into the Mirror World, those without an Advent Deck can't leave, not even being carried by someone with a Deck.
It remained unaffected in the canon ending of the special, but in an alternate ending, Shinji as Knight Survive used his Final Vent to destroy the Core Mirror, destroying the Mirror World and the other Riders in the process. However, as Shinji tried going forward with his life, the other Riders soon began appearing in reflections around him, the only explanation offered (by narration) being that human nature willed the Rider Fight to continue, bringing everything back again.
===Kamen Rider Ryuki: Ryuki vs Kamen Rider Agito===
In a dream sequence by Shinji, the Mirror World was instead called the "Miracle World", a fact that confused even him. Its ruler was the Fake Kamen Rider Agito, who controlled the Mirror Monsters, and all Riders fought to protect humanity against them. The real Agito was also inexplicably able to join them. After defeating the Fake Agito, the Miracle World disappeared when Shinji woke up, Ren calling him out for talking nonsense when Shinji at first failed to realize it had been a dream.
===Kamen Rider Decade===
In an alternate reality, the Mirror World had a very different function.
In the World of Ryuki, the Mirror World is the site for the Battle Trial system, where Riders fight for the right to rule on court cases in place of due process by evidence, participants chosen for being career lawyers or for being connected to the case. The Mirror World can only be accessed by Riders (Decade included), and is used as an arena so fights can happen without interrupting the real world. Riders who lose in the Mirror World are ejected unharmed. Only one without-context scene shows non-Contract Mirror Monsters, so it is unclear what if any presence or function wild Monster serve.
It remained unaffected by the end of the arc.
===Kamen Rider Wizard===
In the world within the Magic Stone, young Haruto used a Rider Ring to summon Ryuki, who safely contained Rinko, Shunpei, and Wajima within the Mirror World while he escaped the Antique Shop Omokagedo with Koyomi. In contrast to what was seen in the prime Mirror World, the untransformed humans remained unharmed. Soon after, the residents were found trapped behind a mirror by the prime Haruto Soma and Kosuke Nitoh, the former of whom used the Clear Wizard Ring to enter the Mirror World and retrieve them. It was at this point that Ryuki appeared and pleaded to Haruto to save the children as he released everyone from the Mirror World. 
In the Mirror World, the screen is actually reversed as seen on Ryuki's V Buckle.
===Kamen Rider Zi-O===
The Mirror World is shown to still exist, despite the entire events of Kamen Rider Ryuki being undone, by the creation of Another Ryuga. It is possible that the Mirror World encompasses any and/or all alternate continuities, shown by the fact that Dark Shinji from the Episode Final timeline exists in this Mirror World and is stated by the Time Jacker Heure to indeed be the same Dark Shinji from that continuity, with his memories intact, due to the fact that he cannot die as long as Shinji Kido lives. There is also a high possibility that the continuity from Episode Final is now embedded into the main timeline.
Heure, having learned about Mirror World from Tsukasa Kadoya, is able to make contact with Dark Shinji by repeatedly breaking a mirror until it connects to the Mirror World, and forms a contract with him, turning him into Another Ryuga. Another Ryuga ran amok in the real world and defeated Kamen Rider Zi-O and Geiz at least five times due to his ability to reflect all their attacks. Shinji Kido learned about the Mirror World's existence, covering any reflective surface in his apartment to hide the fact that he now lacks a reflection, but was attacked by Dark Shinji (presumably). While trying to stop Another Ryuga from escaping into the Mirror World, Zi-O is dragged in as well, and when he awakens, he soon meets his own Mirror World duplicate, who transforms into a mirrored Zi-O and attacks him. 
To settle the arguments between him and Shinji and their duplicates over who is the real them, Sougo concludes that their Mirror World counterparts are the dark sides of them, but are no less them, and they must accept that that part of them exists to be truly complete again. This acceptance lets Sougo unlock the new power of Zi-O II, which he uses to defeat Another Ryuga, conveying to Dark Shinji that Shinji accepts him, too, settling their ongoing feud. Shinji reconnects with his old editor-in-chief, having regained his reflection. 
=== Kamen Rider Outsiders ===
Many years later, after the timeline reset, it was revealed that the Mirror World was frozen ever since Shiro Kanzaki had altered the timeline into a timeline where the Rider Fight did not happen on his little sister's, Yui's, wishes. Shockingly, it also turned out that when Shiro Kanzaki had altered the timeline, all of his research notes regarding the Mirror World and the Mirror Monsters as well as his blueprints of the 13 Kamen Riders' equipment which had been stored in the computer servers of Semeiin University's Ejima Laboratory had, somehow, not been erased by Shiro's timeline reset. Thus, when the secret organization known as Foundation X had decided to hack into said laboratory's computer servers so that they could utilize Shiro's research notes and blueprints as part of one of their projects, they had managed to use the acquired information to restore the Mirror World which had, in turn, restarted the Rider Fight with the victor of said fight being given the position of being a member of a team of Kamen Riders that was being put together by Foundation X. 
==Wizard Ring==
: Its use is unclear, but it appears to allow Wizard to enter the Mirror World. This ring has no official design since the top of the ring is not shown on screen. 
*The equivalent spell in the White Wizard Driver is .
==Notes==
*Notably, throughout Kamen Rider Ryuki, several mysteries concerning the Mirror World were left unexplained, such as how the Kanzaki siblings gained access to the Mirror World, its mysterious inhabitants, and its inconsistent wish-granting capabilities. 
*The ability to see into the Mirror World is inconsistent throughout Ryuki:
**A Monster victim saw Dispider in her mirror (episode 1), Reiko saw Shiro in a reflection on a security tape (episode 26), and Shimada's camera caught Gigazelle in a reflection (episodes 39/40).
**However, it was a plot point that a boy and Goro needed to hold Shinji's Advent Deck to see Knight, Zolda, Abysslasher, and Ouja fighting (episode 27).
*To accommodate the filming of Rider battles in the Mirror World, the designs of Rider and monster suits, along with arsenal, are made mostly symmetrical, with the footage being flipped during editing. Certain props such as Visors and weapons would be placed or held on the opposite side of where they would normally be in the real world, while the V Buckles and the Card Decks would have props of their mirrored versions made as well.
*Strangely, potted plants regularly appear inside the Mirror World, somehow being immune to its destructive properties.
==See also==
*Ventara - American counterpart from Kamen Rider: Dragon Knight
==References==
Category:Kamen Rider Ryuki
Category:Locations