The battle for supremacy begins as the Riders representing Touto and Hokuto finally square off!
We begin the episode with Sento and Kazumi standing opposite each other, with a lot of tension between them, on the temporary arena that was set up for their representative match to try to end the war between Touto and Hokuto. We then briefly cut to Touto’s Himuro Taizen then to Hokuto’s Tajimi Yoshiko, who are both hoping their respective Rider will win. We also briefly see Seito’s Mido Masakuni before returning to the arena.
The referee for the fight announces the victory conditions which are surrender, being unable to continue the fight or forced disengagement of the Rider System, as the camera pans around the arena to show who is present.
After that, we see Sento transform into Kamen Rider Build RabbitTank and Kazumi transform in Kamen Rider Grease while looking at the dog tags of his fallen friend. The referee the declares the fight can begin and we go to the opening credits after the two Riders punch each other.
After the opening credits, we go to Café Nascita in a flashback of the night before, where we see a rather angry Banjou having a go at Sento for his decision to fight in the representative match when Misora gets between them. Sento explains his decision to fight before handing Banjou a banana, calling him a monkey. We also see Sento reach into his pocket after asking Misora for a favour.
We then return to the fight, where Misora pulls out a FullBottle-looking device. We also see that Build and Grease are currently quite evenly matched when Build switches to RoseCopter, much to the surprise of Kazumi’s team as well as Yoshiko, then he starts to gain the advantage over Grease. Grease then questions how Build got Hokuto’s FullBottles just as Build switches to TigerUFO and starts winning against Grease.
We then cut to Banjou as he starts to take more interest in watching the fight unfold, before going back to the arena briefly to see Grease notice Build is now using Seito’s FullBottles. He realizes it was Blood Stark who gave them to Sento. Blood Stark shouts “Bingo” in confirmation as Yoshiko questions his actions.
As we return to the action, Build changes form again, this time using WhaleJet to disrupt an attack, then GiraffeCyclone for a Vortech Finish. Grease starts to get angry, which in turn raises his Hazard Level. We cut to a flashback where we see Kazumi volunteer for the process to become a Kamen Rider; he and Blood Stark exchange some dialogue, including to agree to act like Kazumi lost his memories around his friends.
Back at the fight, Grease starts to take back the advantage that Build had gained before another flashback of Kazumi’s team telling him they had volunteered for the experiments that made them into Hard SMASH. We also see Grease training with Blood Stark.
In the arena, Grease starts to subdue Build by using a Scrap Finish. As Blood Stark and Yoshiko watch the fight on television, Yoshiko admits that she’s sent all of Hokuto’s military might towards Touto so she can crush Touto if Grease loses against Build.
In an attempt to shift the momentum back his way, Build uses RabbitTank Sparkling and the Beetle FullBottle to perform a Vortech Break on Grease, who gets even more worked up. They both perform powerful Rider kicks as Build pulls out the Hazard Trigger.
In our final flashback of the episode, this time involving the weird FullBottle-looking device from earlier, it is revealed that the bottle is a switch that is designed to destroy the Hazard Trigger along with Sento should he go out of control again.
Build changes into RabbitTank Hazard and proceeds with easily beating Grease down. A cut to Nascita shows Sawa telling Banjou that Build has used the Hazard Trigger.
Build continues to beat down Grease when he starts to go berserk; he changes to HawkGattling Hazard before charging up a Hazard Finish, forcing Grease out of his transformation and winning the representative match for Touto.
We then cut to various people cheering that Build won, including Taizen. We briefly see Yoshiko, who can’t believe Grease lost as we go back to the arena and Misora, who looks concerned at the fact Build hasn’t disengaged his transformation yet.
Build then walks to towards Kazumi and tries to attack him when, out of nowhere, Cross-Z Charge gets in the way, saving Kazumi. Cross-Z Charge starts fighting Build in order to disengage Build’s transformation but struggles at first as he can’t quite control the Sclash Driver. After Banjou realises he’s the only one able to stop Build, he manages to get control over his power and continues the fight against Build to a point where both Rider’s transformations disengage.
As Sento comes to from going berserk, Banjou explains to him that he won the fight. We then see Kazumi exchange some dialogue with his team then cut to Hokuto where we see Blood Stark stop Yoshiko ordering her army to invade Touto just as some of Seito’s Guardians burst in. Blood Stark then reveals that he was never really trying to help Yoshiko in the first place.
We then see Masakuni order his Guardians to take Yoshiko into custody, which then reveals that this was his plan all along. We see a mysterious purple Kamen Rider walk in dragging a destroyed Hokuto Guardian with him. Blood Stark announces the purple rider Seito’s Kamen Rider as the episode ends.
What did you think of this week’s episode? Did you guess that Build would win the match? Was you expecting Seito to secretly have a Kamen Rider? Let us know in the comments below.