History Film / KamenRiderReiwaTheFirstGeneration

* CurbStompBattle:
** Sure, Will has the powers of a Kamen Rider. But he's a businessman, not a fighter. He's completely defenseless [[spoiler: against the expertly-trained Vulcan and Valkyrie]] and falls to them with ease.

** Another Zero-One is completely defenseless [[spoiler: against the A.I.M.S. Riders]] and falls to them with ease.
** Sure, Will has the powers of a Kamen Rider. But he's a businessman, not a fighter. He doesn't even last a minute against [[spoiler: the expertly-trained Vulcan and Valkyrie]].

* ScrewThisImOutOfHere: After getting beaten by Geiz, Woz and Tsukuyomi, Horobi and Jin flee then be destroyed.

* CurbStompBattle: Another Zero-One is completely defenseless [[spoiler: against the A.I.M.S. Riders]] and falls to them with ease.

* RealityEnsues: Sure, Will has the powers of a Kamen Rider. But he's a businessman, not a fighter. He doesn't even last a minute against [[spoiler: the expertly-trained Vulcan and Valkyrie]].

* RobotKid: The first sign that history has been changed is that Aruto sees a group of [=HumaGear=] children going to school, when [=HumaGear=] children don't exist in the normal timeline.

''Kamen Rider: Reiwa The First Generation'' is the eleventh annual ''Franchise/KamenRider'' Movie War {{crossover}} film and the first of the Reiwa era, serving as a crossover between ''Series/KamenRiderZiO'' and ''Series/KamenRiderZeroOne''. It was released on December 21, 2019.

** Isamu and Yua discussed about killing each other one day shall they become a Humagear is mirroring the climax episodes of the Workplace Competition Arc in which [[spoiler: Yua remains on the side of ZAIA Industries as the Jackal Raider and Gai's weaponization of Fuwa's head-chip containing Naki's HumaGear data]].

** Isamu and Yua discussed about killing each other one day shall they become a Humagear is mirroring the climax episodes of the second arc and the early episodes of the third arc where [[spoiler:Isamu faced Yua for choosing the evil side and Yua became a monster of the series and human becoming the evil Humagear is referring to the Raider.]]

* SuperPrototype: Ichi-Gata is [[spoiler: the foundation for what would become Kamen Rider Zero-One]]. 001 is only able to stand up to it at all due to it sharing Ichi-Gata's SuperSpeed. It outclasses him in every other way.

* AnAesop: [[spoiler: Don't try to pine over the past. Work to change what will be, instead]].

* [[RememberTheNewGuy Remember the New Girl]]: Finis was [[spoiler: one of Swartz's supporters]] and interfered in Zero-One's timeline to lure Sougo there and take revenge on him. She never comes up during the show.

* RealityEnsues: Sure, Will has the powers of a Kamen Rider. But he's a secretary, not a fighter. He doesn't even last a minute against [[spoiler: the expertly-trained Vulcan and Valkyrie]].

* FragileSpeedster: The only thing Kamen Rider 001 has going for it is its SuperSpeed. It sucks at everything else.

* StillWearingTheOldColors: Fuwa and Yua's outfits are made from [=A.I.M.S.=] fatigues.

* StableTimeLoop:

* EarlyBirdCameo: TheStinger shows the first appearance of Kamen Rider Thosuer.

* {{Foreshadowing}}: There are several scenes in the movie that foreshadowed the future events of the main series:

** Resistance against Hiden as the fact that Aruto and Isamu will face against Hiden Company as it has been taken over by Gai starting on third arc.

** Will's concern of the Humagear's future has foreshadow on Jin after his resurrection and Jin explains himself about thinking the future of the Humagear on the third arc.
** Will wouldn't be the first Humagear to betray Hiden Intelligence's CEO on what they stand for, [[spoiler:as the Humagear MC Check-It-Out did in regards to be exposed to political corruption by ZAIA's representative that led to him choosing to become Dodo Magia willingly that led to ZAIA taking over Hiden via Workplace Competition's last round.]]

[[NotSoWellIntentionedExtremist Under the pretense that she seeks to erase the losses of that day]], a new Time Jacker by the name of Finis travels to the past of Aruto's world, creating the Zero-One Anotherwatch and entrusting it to Korenosuke Hiden's secretary, Will. Now Another Zero-One, Will prematurely murders Korenosuke and takes over Hiden Intelligence, rallying every single [=HumaGear=] to declare a RobotWar on humanity.

** Will wouldn't be the first Humagear to betray Hiden Intelligence's CEO on what they stand for, [[spoiler:as the Humagear MC Che.ck-It-Out did in regards to be exposed to political corruption by ZAIA's representative that led to him choosing to become Dodo Magia willingly that led to ZAIA taking over Hiden via Workplace Competition's last round.]]

Luckily, Aruto isn't alone. Izu is still by his side even as a complete nobody in this new timeline, and Sougo, Geiz, and Woz are in hot pursuit against Finis's attempts to resume the chaos Swartz sought to bring upon their own world. Together, the four learn not only the truth of what brought them altogether and how Aruto became Zero-One, but also what it truly means to live for the present and change the future.

** Izu announced herself for wishing to be with Aruto during her execution, mirroring [[spoiler: the first episode of the third arc where Izu initially chose to return to Hiden but finally deciding to side with Aruto for his guts to keep on doing what is the best for Humagear and humanity.]]

* RippleEffectProofMemory: [[spoiler: It's heavily implied at the end of movie, Izu is the only one that still have the memory of the event of the altered timeline.]]

* RippleEffectMemoryProof: [[spoiler: It's heavily implied at the end of movie, Izu is the only one that still have the memory of the event of the altered timeline.]]