This article is about a/an episode in Kamen Rider Zi-O.

Best Match 2017 (ベストマッチ2017 Besuto Matchi Nisen-jūnana) is the second episode of Kamen Rider Zi-O. It is the second part of the Kamen Rider Build tribute arc. It features the full debut of Geiz's GhostArmor after its brief appearance at the end of episode 1 and the series debut of Zi-O's BuildArmor after its appearance in Kamen Rider Build: Be The One. Emu Hojo makes a brief return at the end of this episode.

This episode is accompanied by the second episode of Kamen Rider Zi-O: Supplementary Plan web series, Rules of the World.


Sougo is attacked by a Kamen Rider from the future, Geiz Myokoin, but is saved by a girl from the same future Tsukuyomi, who wishes to help him out. With no clear idea of what is going on, his confusions are further pushed with frequent visits from the mysterious prophet named Woz. Meanwhile Another Build is wreaking havoc, and Sougo discovers that the key to defeating this "Kamen Rider Build" is to meet Sento Kiryu.

Continuity and Placement

  • The past, 2017: Take place between episodes 12 and 15 of Kamen Rider Build. The ending leads to an altered timeline rather than continuing in Build TV series. Sento has now mentally reverted to Takumi Katsuragi and his and Ryuga's powers are gone. The consequences of this alteration to time are not shown.


"According to this book, in September of 2018... The ordinary high schooler, Sougo Tokiwa has a future wherein he becomes the demonic king of time, Ohma Zi-O. In order to prevent this, Geiz and Tsukuyomi arrive from the future. However, Sougo Tokiwa chooses to obtain the power of Kamen Rider Zi-O and defeat Another Build. Then, Zi-O steals the power of Kamen Rider Build, taking his first step to becoming the demon king... Oh! Perhaps I've read too far ahead."
Picking up where the pilot left off, Zi-O is under attack by Geiz in his Ghost RideArmor and the Ghost Parkas. Despite this, Zi-O refuses to fight back. Geiz executes an Omega Time Burst Rider Kick to go for the kill, but Tsukuyomi blocks and deflects the kick with Zi-O's Time Mazine, telling the Rider to run away. Zi-O sees a Ridewatch on his wrist with the word "Bike" on it and uses it to summon the Ridestriker to escape. Tsukuyomi tries to block Geiz's path, but he summons his Ridestriker and chases after Zi-O on the road, only for Zi-O to jump off the bike and hide behind a concrete ramp where Geiz cannot see him and continues down the road. Geiz stops and in anger asks why Tsukuyomi why she let Zi-O escape, to which she answers that she isn't sure. Annoyed, Geiz tells her not to interfere again as he must kill Zi-O to save the future.

Heure finds the basketballer lying on the ground near a bush and is playing leapfrog over his unconscious body. Heure isn't concerned at Zi-O gaining his power as destined in prophecy, as things can still go according to his plans. He wakes up the basketballer to resume Another Build's reign of terror, first removing the weakened Another Ridewatch from the basketballer's body and restarting it. Heure then re-inserts it to transform the baskeballer back into Another Build.

As Sougo runs home and is nervously looking over his shoulders to ensure none of the people trying to kill him are following, he is greeted by Woz. Sougo demands to know what his deal is and if he is a friend of Tsukuyomi and Geiz. Woz simply states he is the only true ally that Sougo has and that according to the Ohma Advent Calendar, Sougo will be destined to rise as the King of Time and ruler of Earth through campaigns of conquest. He also explains that the Time Jackers are trying to stop Sougo's rise to power by attempting to groom others to become the Demon King. Thus, he is the only being trying to protect history as it has been written in his book while all the others are vying to change history. Woz assures Sougo he will do everything in his power to guide his majesty to his pre-destined path in history safely. A shrine gong unfreezes and rings (implying that Woz froze time), and when Sougo turns back to Woz, he sees that the prophet has vanished.

As Tsukuyomi and Geiz search for Zi-O, they hear two baseball players screaming for help as Another Build turns one of them into a Smash Bottle. Tsukuyomi is confused as they already defeated Another Build, but Geiz realizes this means the Time Jackers are in this era and causing trouble. Geiz shows no sympathy for the remaining baseball player, insisting to Tsukuyomi that they leave him to die so they can continue their mission. Tsukuyomi naturally rejects this and Geiz reluctantly decides to help the baseball player by transforming and fighting Another Build.

Sougo finds Woz appearing in his home, who forgot to mention that Another Build is still out there and the Time Jackers have altered history, thus the creature is now Kamen Rider Build. Sougo wonders what happened to Sento Kiryu, but Woz doesn't know. Woz says that as Sougo is now, he cannot defeat Build, though Geiz is trying his best to defeat him. Upon arriving and saving Geiz, Zi-O finds that Another Build has become even stronger thanks to consuming the baseball player's Smash Bottle. He uses his Jikan Girade as a baseball bat to slice and deflect the ball energy projectiles and then asks the two time travelers if they are alright before engaging the monster again. Tsukuyomi wonders if they have got the wrong person as Sougo seems kind and wants to protect them. Zi-O uses his Rider Kick, but Another Build just reappears after being blown up. Sougo thinks he can get help from the real Kamen Rider Build and runs to nascita to find Sento, leaving Geiz to face Another Build on his own.

Soguo goes to the cafe and opens the fridge, only to find the entryway to Sento's lab is gone and the fridge is just an ordinary refrigerator. Sento and Ryuga enter, having returned from a Tsunagiz concert and are acting strange, saying they don't remember meeting Sougo and behaving like morons, with Ryuga calling Sento "Takumi". They claim that nascita is the Tsunagiz Fan Club and have no memories of being Kamen Riders. Meanwhile, Geiz tries to defeat Another Build with his Rider Kick, which causes the two Riders to have their Ridewatches appear and they suddenly remember who they are. Sento and Ryuga remember Sougo and after Sento sees a brief memory from the past in 2017, he entrusts their Ridewatches to him to "give their regards to their past selves".

As he leaves, Sougo at first doesn't get it but soon realizes that Sento was hinting to go back to 2017 to stop Another Build. Geiz is still trying to defeat Another Build in 2018, but he keeps re-spawning every time. Exhausted, Geiz's transformation shuts off and he falls to his knees. Sougo runs back and gives Geiz the Cross-Z Ridewatch,saying they need to go see Kamen Rider Build in 2017 to stop Another Build. Both of them get into the Time Mazines and jump to 2017, where Another Build is terrorizing the citizens. The monster turns two students into Swimming and Archery Smash Bottles before deciding on attacking Ryuga and Sento in the past. The two notice the monster isn't a Smash, but know they need to try to stop it. They both transform into Kamen Rider Build and Cross-Z, but their efforts are no good. Time distortions cause the power of their Drivers to flux as their powers fade in and out of temporal existence due to the presence of the evil Build, with the phony Rider's latest Smash Bottles boosting its power and agility to overwhelm them. The Time Mazines ram Another Build and the two Riders try to meet up with Sougo and Geiz, only to be frozen by Heure. Heure insists that Zi-O not interfere with his plans to create a new king before taking his leave.

Sougo and Geiz transform, which unfreezes Build and Cross-Z. The quartet of Riders try to fight briefly together, but Build and Cross-Z's powers fade away from time. Zi-O uses his Build Ridewatch to summon the Build RideArmor and equips it. He then works with Geiz using the Cross-Z Ridewatch to do a double finisher to finally take down Another Build.

Upon the defeat of Another Build, the Another Ridewatch shatters and the basketballer awakens back in 2017 with no memory of what happened. But his fate was still altered as the cars still crashed into each other and the black one did not hit him. Sougo tries to return Ryuga and Sento's Ridewatches to them after Geiz mentions that they didn't have them in this time (thereby creating a time loop where either way Sougo gets the Ridewatches). But Sento Kiryu no longer exists as Takumi Katsuragi is in control of Sento's body, but shows interest in the now sealed Ridewatches. Ryuga refers to him as Takumi too. The attempt to restore history had failed, but Sougo believes that Sento will come back and choose to be Kamen Rider Build again someday. The two fly off in their Time Mazines back to 2018, with Takumi and Ryuga witnessing this as Sougo waves goodbye to Takumi in his Time Mazine.

Later that night, Geiz and Tsukuyomi wonder if Sougo truly is the future Demon King based on his heroic actions. Geiz thinks Sougo will still become the evil Zi-O based on the fact he has gained Build's powers and Kamen Rider Build has been erased from history, thus the events that led to the bad future they live in are already set into motion. Sougo wakes up the next morning only to find that his uncle has found a renter for the second room in the house and that it is Tsukuyomi and Geiz who are going to be living with him. Tsukuyomi makes it clear that they are just observing him and Geiz whispers to Sougo that he will kill him if given the chance. The trio sit down to an awkward breakfast, with Sougo telling his uncle they will all try to get along as roommates.

"And thus, Zi-O obtained the power of Build. His path of conquest had only just begun. However, his meeting with another legend is already at hand...."
―Woz reads from the next pages of the Great Calamity Calendar[src]

As Woz reads from his tome, a familiar hospital hallway is shown with a doctor walking towards the pediatrics ward, revealing to be Emu, also known as Kamen Rider Ex-Aid...


Guest Cast

Suit Actors

Forms and Collectibles Used



  • Bottle used:
    • Build
      • Biotic: Rabbit
      • Abiotic: Tank
    • Cross-Z
  • Form(s) used:
    • Build
      • RabbitTank Form
    • Cross-Z
      • Cross-Z


  • to be added


Build Cross-Z Watch CS
  • Closing Screen Ridewatches:
    • Kamen Rider: Zi-O & Geiz
    • Ridewatches:
      • Zi-O: Zi-O, Build
      • Geiz: Cross-Z
  • Count at episode end
    • Watches in Zi-O's possession: Zi-O, Build, Bike
    • Watches in Geiz's possession: Geiz, Ghost, Drive, Cross-Z, Phone, Bike
    • Watches in Tsukuyomi's possession: Phone
  • Part of the reason that Build's (and beyond up until Blade's) history was not corrected is due to a "bootstrap paradox", a time travel scenario where an object or an event caused by a time traveler negates its original origins creating a causality loop that breaks time at a specific point. An example is if Einstein was told the theory of relativity by a time traveler before he actually created it and then the traveler returned to the future, Einstein would then take credit for the theory. Since every concept needs a temporal point of origin, it would violate that since the time traveler knew it from Einstein who learned it from the time traveler, thus creating an infinite loop.
  • Due to the alterations of the history in which the events of the Kamen Rider Build series were removed from the timeline, the Cross-Z Ridewatch is created in a different way in this episode, opposed to Build's final episode where it was created right after the merging of the two worlds.
  • Although Build's history being erased, Sento/Katsuragi still keeps Taro Sato's face, a fact that was acknowledged in Episode 2.5 Rules of the World.
  • The Rider Armors used relate to Riders who used an alternate form in the first episode of their show.

External links


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