Episode 1
Sento Kiryu starts his new job at the Touto Institute of Advanced Matter Physics, researching the mysterious Pandora's Box. While responding to a potential Smash sighting, Sento comes across a wanted fugitive...
Episode 2
The Kamen Rider of Touto is now a fugitive, due to his part in saving a convicted murderer - Ryuga Banjo. Kiryu begins to see similarities in the mysterious experiments both he and Ryuga were subjected to.
Episode 3
The investigation into Ryuga's kidnapping leads to a man named Nabeshima. But to get the answers he needs, Ryuga must cross the border to Seito...
Episode 4
The mysteries of the past continue to pile up as Sento investigates the Pandora's Box disaster. In Seito, Ryuga and Sawa continues the search for Nabeshima's family.
Episode 5
Sento confronts Owner on his involvement with Faust. Sawa finds a lead on Sento's elusive past.
Episode 6
Ryuga finds the entrance to Faust's hidden base. Aiming to learn more, Sento learns of the late Katsuragi's research into "Nebula Gas".
Episode 7
Sento and Ryuga need to learn more about Katsuragi and his research. Setting their sights on Hokuto, they first have to get through the Sky Wall...
Episode 8
Now hidden in Hokuto, Sento and Ryuga try to learn more about Takumi Katsuragi from his mother, and find his hidden project data.
Episode 9
A debate about the nature of Katsuragi's research leads to another falling out between Sento and Ryuga. Under pressure from a backer, Faust hatches a plan to steal Pandora's Box.
Episode 10
As the three Prime Ministers of Japan meet, Blood Stark leads an attack on the Touto Institute of Advanced Matter Physics.
Episode 11
With the majority of his Full Bottles now in Night Rogue's possession, Sento reveals his trump card - a way for Ryuga to use the Build Driver.
Episode 12
Sawa reveals a connection between Faust, Nanba Heavy Industries, and the Touto Government. Sento and Ryuga plan to recover Pandora's Box.
Episode 13
A surprise call from Nabeshima lays the foundation for Sento's plan to reclaim Pandora's Box, and a chance to capture the elusive Blood Stark...
Episode 14
Blood Stark's identity is revealed, and Sento races against time to finish a counter-measure against him.
Episode 15
With Pandora's Box safely in their possession, Sento and Ryuga go after Gentoku, set on revealing the link between Touto's government and Faust to the public.
Episode 16
Gentoku reveals the truth behind Sento's missing memories, and the reality may tear his and Ryuga's friendship apart.
Episode 17
Hokuto invades Touto, looking to claim Pandora's Box for themselves. As civilian casualty numbers raise, Gentoku's government instigates Kamen Rider as their military weapon.
Episode 18
A new contender in the Rider Wars appears before Sento and Ryuga, somehow weilding his own Sclash Driver. Hokuto's own Rider, Grease, has arrived.
Episode 19
Another clash between the Touto and Hokuto Riders ends with Ryuga struggling from the Sclash Driver's effects. The Hokuto Crows are given a way to power up by Blood Stark, but there's a cost...
Episode 20
Soichi gives Sento the means the stop Ryuga's growing rage with the forbidden item - the Devil's Trigger. Gentoku plots a counter-attack against Hokuto's invaders.
Episode 21
In order to counter Ryuga's rampage as Cross-Z Charge, Sento is forced to use the Hazard Trigger. What is the cost of using this forbidden item?
Episode 22
Touto and Hokuto's governments have ordered a winner-takes-all battle to decide who keeps Pandora's Box. It's Build vs Grease to decide the victor of the Rider War!
Episode 23
Seito delivers an ultimatum to Kazumi - fight for them as their Kamen Rider or witness the death of his family. A mysterious new adversary makes his way to Touto to confront Sento and Ryuga.
Episode 24
Kamen Rider Rogue has revealed himself; Misora collapses inside the base.
Episode 25
Misora sends Kamen Rider Rogue flying through Skywall; Souichi reveals to Sento that there is a spy in the Touto government.
Episode 26
Seito challenges Touto to a best-of-three battle to decide who keeps Pandora's Box; Sento works to find a counter to Black Hazard's berserk state.
Episode 27
Ryuuga is tricked into losing his match; Build and Rogue face off as Sawa arrives with the schematics stolen from Sento.
Episode 28
Kamen Rider Rogue receives the data on Build's Rabbit Rabbit form, forcing Sento to unleash Tank Tank form; Sawa's backstory is revealed while Kazumi rescues civilians; Nanba decides to not play fair, taking control of Seito and declaring war.
Episode 29
Despite their promises, Seito continues their assault against Touto. All this is made worse as Blood Stark completes a panel of Pandora's Box, and the Skywall begins to shift...
Episode 30
Blood Stark wonders how the Queen of Mars is still alive. Mysteries begin to arise as she singles Ryuuga out to become hope.
Episode 31
Sawa and Misora discuss what the story behind Ryuuga really is; Team Build raid Pandora's Tower in an attempt to reclaim Pandora's Box, but Blood Stark stays one step ahead, goading Ryuuga into action.
Episode 32
Ryuuga learns of his alien origins; Nanba takes Kazumi's friends hostage in exchange for Pandora's Box.
Episode 33
Souichi holds the Touto Prime Minister hostage in exchange for Sento to give him the Evol Driver.
Episode 34
Sento is poisoned by Evolt, who then negotiates a deal with Ryuuga for the cure.
Episode 35
Evolt is now in possession of Ryuuga's body and goes after Pandora's Box. Sento reaches out to Gentoku, who has the last of the bottles.
Episode 36
Pandora's Tower is complete and Evolt stands ready to destroy Earth. Kazumi is still angry with Gentoku for killing his friend and challenges him to a fight; Sento works on a way to harness Pandora's Box into a power-up for Build.
Episode 37
In order to keep Evolt from getting Pandora's Box, Bernage moves the entire cafe to a different location; Ryuuga can no longer transform and so he and Kazumi go to Gentoku for help in saving Sento.
Episode 38
Sento has now lost all his memories and reverted to Takumi Katsuragi; Evolt gives Utsumi and the rest of Nanba an ultimatum.
Episode 39
Utsumi has now taken on the role of Kamen Rider Mad Rogue; Takumi creates a new bottle to fight Evolt, but also plans to take out Ryuuga as well.
Episode 40
Kazumi is bummed that Evolt has stolen the bottles of his lost friends. Sento travels to his mother's house in Hokuto for answers about his father, but he and Kazumi end up face to face with a new Smash.
Episode 41
Sento learns that his father actually is alive; Sawa goes to find the one Faust experiment that, to their knowledge, has no relation to the Kamen Riders; Misora discovers that the Best Matches are about her.
Episode 42
Sento suspects that since Evolt has the Lost Bottles, he also has his father; Evolt plans to reunite Japan while Gentoku mopes over his dead father.
Episode 43
Sento's loyalties are questioned concerning his father; Misora makes a deal with Evolt.
Episode 44
Kazumi and Gentoku get caught in order to raise their hazard level; Sento builds Ryuuga a new power-up.
Episode 45
It turns out that Evolt is still alive, but Sento's father is able to tell him about a secret white panel in Pandora's Box.
Episode 46
Evolt reveals himself to the world; Sento plans to combine their world with a parallel world via the white panel; Kazumi asks for a new power up.
Episode 47
Kazumi uses his new weapon to battle the clones of his former friends; Gentoku does battle with another set of clones and gets help from an unlikely ally.
Episode 48
With Kazumi now gone, it's time for the final confrontation with Evolt.
Episode 49
Ryuuga has flown away with Evolt. Sento decides to go bring him back as the two worlds are about to merge.
