Haruto and Koyomi wake up to find themselves on the same rooftop, but spot a tall, unfamiliar tower in the distance. Exploring the city, they find a lot of citizens display their ability to perform magic tricks with their belt as they also use it for their daily life. Shunpei appears as he rescues a kid via Giant Ring and Haruto and Koyomi greets him but Shunpei claims not to know them or never meet them before.
Finally, Haruto and Koyomi reveal that they are from different dimensions with Shunpei becoming fast friends due to his childhood desires to meet otherworldly humans. The trio goes to the alternate version of Donut Shop Hungry where Haruto realized that the their currency is mana and that Yens and other coin/money notes didn’t exist as it will be paid via a Magic Scanner (a Hand Author-esque cash register). As Haruto about to eat his donut, suddenly, an army of Ghouls lead by a Phantom named Khepri appears and attacks the citizens in order to bring them into despair. Soon, Rinko appears and transforms into Kamen Rider Mage followed by Shunpei, Donut Shop Hungry Manager and Worker, and two other citizens to fight much to Haruto's surprise. The Donut Shop Hungry Staffs finish the Ghouls by binding them with Donut Ring and hit them with a giant hammer in a similar manner to Daruma Otoshi. Haruto transforms and tries to help, but only finds himself getting in the way. All Mages bind Kherpi with Chain Ring, giving Rinko an opening to finish him with Kick Strike. After the battle, Haruto and Koyomi introduce themselves as other dimension humans only for Rinko to handcuffed them as she thinks something is strange. She brings them to Emperor Maya whom Haruto asks him whether he is powerful or not so much that he can even recreate the world. The emperor (silhouetted under a curtain) attacks him with a lightning spell but later stops when taking an interest to Koyomi who is not a mage. Outside the castle, Haruto and Koyomi reveal that they’re looking for the Golden Magician whom brought them here in the first place.
However, instead they were brought to the alternate Kosuke Nitoh/Kamen Rider Beast whom coincidentally also uses the title Golden Magician. As Haruto and Koyomi about to leave, Kosuke stops them, taking an interest at the duo for being otherworldly people. Rinko introduces Kosuke as a professor who refuses to use regular magic that is possessed by citizens but instead uses magic he invented himself. His Beast Driver is handmade as he referred it to an old book and that it never needs the user to consume Phantom manas to survive.
While taking a walk, they stumble across a Magic Ring Shop (the world’s counterpart of Okagedomo Antique Shop). When a customer wants to know the function of the Flexible Magic Ring, Wajima appears, transforms into Mage to demonstrate the power much to the customers’ disgust as they walk away from the shop save Koyomi and Haruto. Wajima introduce them to his worker, Shiina whom he also gave shelter after his parents passed away. Temporarily, Wajima offers the duo shelter too as Haruto reveals how he and Koyomi got into their world to Shiina only to cause him to run away from the shop. Wajima reveals that Shiina’s mother and almost everyone were taken away by a giant rainbow tornado with the victims nowhere to be found. He also had met Emperor Maya and requested him to bring the victims back which he agrees and will try his best. However, when the Emperor knew that Shiina had given his mother a ring that same day (his first home-made one) the boy had started to suspect that Maya might know more about, or possibly even be responsible for, his mother's disappearance.
While Haruto and Koyomi are trying to find Shiina, the Golden Magician appears and uses his Tornado Ring to cast away a group of female street dancers into a rainbow Tornado. He walks away, unknowingly watched by Shiina whom suspects him to be Emperor Maya. Meanwhile Koyomi meets an unfamiliar man on the street, who sympathizes with her over her lack of magic, telling her he knows what its like to be different from everyone else. While Shiina chases the Golden Magician, this eventually leads him to Phoenix, Medusa and Gremlin who, in this reality, work as a trio to drive others to despair. Shiina transforms and begins to fight. When Haruto was chasing for Shiina, he encounters Kosuke, who tries to fish for mayonnaise, much to Haruto’s shock. Haruto asks whether he has seen Shiina or not but later is interrupted when they realize that Shiina is under attack. As they arrive, Shiina has been defeated and is about to lose to his despair. Haruto and Kosuke transform and, using the powers of the Drago Timer and Beast Hyper, manage to kill the Phantoms. The two then dive into Shiina’s Underworld and initially find themselves in Shiina's memory of giving his mother the Flower Ring on the day she was abducted. Suddenly the Ouroboros Phantom, a two headed snake, emerges. Haruto and Kosuke manage to trick the inner Phantom into tying itself into a knot, and use thie chance to perform Kick Strike, with both of their Phantoms transform into their Strike Phase, and destroy Ouroboros.
Shiina awakes, revealing he saw the Golden Magician retreat to Maya’s castle, believing Maya is the culprit. Haruto calms the boy and prepares to investigate the castle again. As he manage to sneak into the castle with Kosuke, they then enter a chamber that shows a machine which has dozens of skeletons stacked on the top. Kosuke then reveals to Haruto that the machine is a Thanatos Vessel, a forbidden device created from humans designed for storing large amounts of mana. Haruto realizes that the Magic Scanners in the city are what's collecting the mana from people, but then notices that one of the skeletons is wearing the Flower Ring, making him realize the corpse is that of Shiina's mother who was killed to create the vessel among with countless other innocent people. As they hear footsteps, they hide as the emperor was having a meeting with the Prime Minister about the machine. After the meeting, the emperor then reveals the purpose of using the machine by draining the citizens' magic. Kosuke accidentally got their cover blown as they escape from the emperor. While running, Kosuke tells Haruto that the machine could be used to reverse the polarity of all the magic in the world, with the sudden shock killing all the mages. Suddeny Sorcerer appears and attacks them as they transform, Beast lets Wizard escape to tell the citizens of the emperor's plan as he continues to fight Sorcerer alone. Sorcerer overpowers Beast as he uses the Vanish Strike Ring to finish off Beast. Back in the shop, Shiina begins to panic as he finds that he can no longer use magic and Koyomi explains that in order to save his life Haruto had to destroy his inner Phantom as well as the boy's ability to perform magic. Shiina gets upset, not knowing how he will survive in a world where magic is used for everything. Haruto tries telling his friends about the emperor's plan as no one believes him as the emperor makes an announcement of capturing Haruto and telling the citizens a lie about Haruto's plan. Koyomi recognizes the emperor as the man she met the previous evening, and remembers how he seemed to understand the pain of not having magic.
After the announcement, guards appears to capture Haruto as he rides his Machine Winger to escape from the guards. While being chase by the Mages, Haruto transform and outsmart them. Wizard then shoots the Magic Scanners until the Captain of the guards stops him. The captain transform and fight Wizard as he still trying to tell them the truth. The citizens started to hate Wizard after hearing what the emperor said as they throw stuff at him, until Koyomi stops them. She then defends Haruto along with his friends as Koyomi tells him that the emperor is suffering alone. Haruto decides to ride to the castle as Rinko and Shunpei transform to fight the guards. Overpowered by the guards, Kosuke arrive and reveal to the captain that he survive Sorcerer's attack as he transform and overpowers the guards. As Haruto arrive to the chamber, he was too late to stop Maya from activating the machine as Haruto, Kosuke and the citizens starting suffering from its effects (apart from Koyomi and Shiina, the only other people in the city without magic). Haruto doesn't understand why Maya is doing this since he'll die too, but Maya reveals that he is not a magician... he was born without magic, and Prime Minister Orma has been working to make it appear that he does so as not to shame the royal family. Maya then tells Haruto that he is tired of living a lie and wants to be free. However something goes wrong, instead of simply killing everyone in the city, they are all driven to despair and their Phantoms start to emerge. Sorcerer enters the chamber as he reveal himself to be the Drake Phantom and telling Maya the true purpose of the machine: getting all the citizens falling into despair. Maya is shocked after hearing this, feel as Haruto manages to once again save himself from despair, knowing that he still has hope. He then tells Maya that he will destroy Magic Land as Haruto removes his Common Ring and shatters it. Both magicians transform and fight each other, but Sorcerer is able to overpower Wizard. Before Sorcerer can finish off Wizard, he uses the Flower Ring to distract the golden magician before assuming into Infinity Style. As they are about to finish each other, Sorcerer uses to Final Strike Ring to power up a Rider Kick, as Wizard uses the Finish Strike Ring to transform into Infinity Dragon and uses a Kick Strike. As their kicks collide, Wizard is finallt able to destroy Sorcerer, causing the rainbow tornado to appear which starts reversing the spell which created the alternate universe. Before returning to his world, Wizard tell Maya that they will meet again in their world, and Maya leaves happily knowing he won't be alone anymore after the change. Haruto finds Koyomi and grabs onto her hand as they are swept away again...
The two wake up to find everything returned to normal with Rinko, Shunpei and Kosuke happy to see they're all right, having been searching for the two for days. Haruto quickly makes sure that Shunpei and Rinko aren't magicians, earning himself a slap from Rinko when he checks her belt, and the group go for some donuts as Haruto tells them of his experience in Magic Land and their alternate counterparts, everyone excited that they were Riders in that world. During this, Haruto and Koyomi spot Shiina, who has been reunited with his mother.
Later, as Haruto and Koyomi reflect on their experience, Koyomi wonders if Maya is happy in this world. Haruto then spots him in the distance with his wife and a young daughter. The two are glad to see that he is no longer alone, and Haruto muses that Magic Land was worth destroying to give him and others that kind of happiness. With that, the two friends head home.
