The intro start showing the red and blue Rider look at the sky wall in the background before reveal it was the title name of Kamen Rider Build.

SINS_COUNTER PRESENT.

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KAMEN RIDER BUILD: THE MARVELOUS GENIUS HERO!

The scene shows many Earths and worlds of the universe before a certain king arrives and looks at Earth which belongs to the Marvel Universe.

Voice: This world seem like is fine but I have a feeling that Neo Faust is involve there...

Then the king look at the world of different version of Marvel's world and he knew he need to find the successor of Kamen Rider Build to stop them.

Voice: Look like I need to recruit the next Kamen Rider Build.

He takes a certain watch with a rabbit-tank face and knows he has to find the successor of Kamen Riders to stop Neo Faust in the new world.

At Japan. Tokyo Metro Science School.

A huge student walk around the hallway and open the door of Science Club room, surprising club members of science club except for one white hair student.

Huge Student: Hey Saito!

White Hair: Huh? What now, Big Oaf. I'm busy.

Huge Student: I need your help! I decide to confessed my love to my childhood crush!

White Hair Student: Finally about to confessing Kasumi? Hoooh... That's interesting... Good luck. Not my problem.

Huge Student: Oi! *Gain a tick mark* You are supposed to help me! How did you confess to your girlfriend before me?!

White Hair Student: Do I look like I give a shit about that, you idiot? *Turn around while continuing his experiment*

The scene show a white hair student reveal himself as he's feels annoyed when the huge student annoyed at him. This is Saito Kirisu the Genius Protagonist of this book.

Saito Kirisu! The Crazy Genius One! The Next Kamen Rider Build!

Saito look at the huge student with his annoyed looks, and wonders why the huge student asked his help because they are both childhood best friends.

Huge Student: That's because I don't know how to confessed to her! Can you help me?

Saito: Here the advice, man up you cowardly shy dumbass. Quit being a pussy. *Rolled his eyes*

Huge Student: What did you call me?! I'm not a dumbass! Now you call me for one time, dude!

Saito: Uh huh... *Ignored*

As Saito ignores his friend but he shouts at Saito as he acts like a gorilla and monkey but oh wait! Then Saito looks at the readers with his smile.

Saito: *Narrating* Yo everyone! I'm Saito Kirisu but you can say that I am the genius student of this school. For myself, I am a huge fan of Kamen Rider especially Build which kinda obvious. But I'm base on Sento Kiryu and Senku Ishigami from Dr. Stone.

Then suddenly Saito narrates about his favorite Kamen Rider Show, Build. He talk about how did he become a genius is because he was got from his father who was astronaut.

Saito: *Narrating* I was inspired to become a scientist like my father became an astronaut. I feel like my father is similar to Sento's father... But anyway, I have to deal with this dumbass.

Saito look back at the huge student before he continue his experiment, Huge Student trying to say to Saito but Saito say something to the Huge student.

Saito: Anyway, good luck on confessing your feeling on Kasumi. I'll shout to show my support for you in this science club room.

Huge Student: Wait really? Thank Saito!

Saito: Urusai, I don't plan to support your huge cowardly shy ass, Big Oaf.

Huge Student: Hey! What do you mean?!

Saito: Beside, you didn't even dare to confess your feeling to Kasumi ever since we were kids for past years ago. It's make no sense, dumbass.

Huge Student: I... *Give up* Okay, that's good point!

The scene shows an angry brown hair man acting like a angry monkey toward Saito while he ignores it. This is Ryuji Baishou the Dumbass Student and secondary Protagonist.

Ryuji Baishou! The King Of Protein And Muscle Head Dumbass Big Oaf! The Next Kamen Rider Cross-Z!

This makes Saito smirk what the author did and gives the nickname to Ryuji before looking at Ryuji as he smirks and makes something interesting.

Ryuji: What's with that smirk?

Saito: Alright, then I'll give you something that interesting and makes sense. *Smirk as grabbing a glass bottle*

Ryuji: Eh? Uso?!

Saito smirk as he holds a bottle contain the liquid which worry Ryuji and club members about what Saito gonna do. Saito has a evil grin that he is planning something.

Everyone in the club react to Saito holding a chemical liquid bottle which they worry about what Saito did and wonder what is the bottle inside there.

Ryuji: What is this, Saito?

Saito: Oh this? This is a love medicine that can speed up the release of the pheromones.

Ryuji: Wait what?! Love potion?!

Saito: Yep, you can surely get Kasumi love after drinking this. *Evil grin*

Ryuji: Ohhh... Souka...

Ryuji look at the bottle while he holding it before he poured it down the sink Saito smirked and Ryuji finally manned up to his crush because Saito was tricking him.

Ryuji: Arigato Saito, but I'm sorry. I won't use such a trick. That's is not soo manly of me!

Saito: I know. *Cross arms* Finally man up huh? Just be yourself and get your girl.

Ryuji: I will! I gonna tell my crush!

Saito: Alright, goes for it. Dumbass Big Oaf. I believe in you. *Smirk*

Ryuji: Thank, gonna go now. Bye Saito!

Ryuji left the club room as one of the classmates asked Saito about the love potion as he wants one of the love potions for the girl he has a crush on.

Random Classmate: Eh Kirisu-San, is that love at first sight medicine real?

Saito: Since that were such a thing? *Took out a match box*

The two Classmates had dirty thoughts while looking at the sink before Saito light up a match stick then he's throw it down the sink Ryuji pour in as it ignited the fire. Causing the two perverts surprised.

Both Classmates: *Surprised* EEK!?!

Saito: It's just a gasoline bottle. It's was made from the cap of an plastic bottle.

Random Classmate: Eh?! Then why are you trick Baishou-San like that?

Saito: *Scoffed* Think about the molecular structure of polyethylene, idiots. But it's just a hydrocarbon in rhe gasoline component. I got it only at glance.

Saito smirked as he explained to his club members, that some smart club members understood but some of the members didn't understand what Saito saying.

Random Classmate 1: No, I don't get it...? *Sweatdrop*

Random Classmate 2: Me too...

Random Classmate 3: If Baishou-Kun drink that, he's would be dead right?

Saito chuckled as he already knew the answer, but some students were confused about what Saito is doing and wonder why he was doing that.

Saito: *Chuckle* Ten Billion Percent that's dumbass surely won't drink it. That serious Big Oaf.

Some students realize that Saito's trick Ryuji to man up but what Saito doesn't know and not awared he was watching by two Riders, one is a certain King Of Time and one is a Genius Physicist.

At The School Ground.

The scene shows a girl seeing the tree with broken Brandes before she removes her neck ties to bandage the broken tree branches. Until Ryuji appears.

Ryuji: Kasumi! Sorry for keep you waiting!

The brown hair girl turned around to see it was Ryuji who had arrived, she smiled at him and knew he was coming to visit her.

Brown Hair Girl: Oh Ryuji-Kun, what's bring you here?

Ryuji: I had something to tell you, Kasumi.

Brown Hair Girl: Tell me. What's the matter, Ryuji-Kun?

The brown-haired girl is confused before she blushes and reveals herself as having brown hair color. This is Kasumi Ito the childhood friend of Saito and Ryuji.

Kasumi Ito! Childhood Friends Of Saito & Ryuji!

Three students look at Ryuji talking to Kasumi as they are chatting and betting money to see if Ryuji gets dumped by Kasumi because she is a popular student.

Random Classmate 1: I bet 100 yen that he'll get dumped by Ito-San. *Grin*

Random Classmate 2: I bet 300 yen that he'll get dumped badly by her.

Random Classmate 3: I bet 500 yen that he'll get dumped even more altogether!

Saito appears as he drinks his soda and has a smirk as he bets his money to see if Ryuji doesn't get dump by Kasumi because he knew them a long time ago.

Saito: I bet 10,000 yen that he'll accidentally not get dumped and succeed. *Smirk*

All 3 Classmates: EH?! MAJI KA!?

Saito: One Billion Percent that's dumbass will succeed. *Smirk*

???: And I bet 20,000 yen like what Saito-Kun said. Soo Baishou doesn't get dumped easily.

Saito smirked as he turned to see it was his girlfriend looking outside the school, he knew she was a bit higher than him and knew who she was.

Saito: Oh, Utaha. Nice seeing you here. *Smirk*

Purple Hair Girl: *Smirk* You too, Saito-Kun.

A girl with purple long hair wearing her lab uniform as she smiles at Saito. This is Utaha Shiraishi, the girlfriend of Saito Kirisu and the girl loves science and president of Engineering Club.

Utaha Shiraishi! The President Of Engineering Club & Saito Girlfriend!

All their classmates are shocked at Utaha money bet is higher than Saito because she bet a higher money than Saito and they were shocked.

All 3 Classmates: EHHHH?! *Shocked* 20,000 YEN!?

Utaha: That's right, I bet 20,000 yen to see Baishou succeed. *Look at Saito with a smile* Like how Saito-Kun once confessed to me before.

Saito: Heh, that is true. *Smile*

Utaha: How smooth you were back then, my Mad Genius Scientist~! *Grin*

Saito: Same goes for you, My Engineer Inventor girl~!

Back to the confession, Kasumi look at Ryuji as he confess his love feeling and say it to her as he hope she accept his feeling.

Ryuji: *Blush* W-Will you be my girlfriend?

Kasumi: Eh? G-Girlfriend?

Ryuji: You see... It's been a long time since I had a crush on you, my heart has feelings for you. I haven't confess my feeling but I want to tell you that I love you!

Kasumi: *Blushes* Ano... Ryuji-Kun.

Ryuji: W-What is it?

Kasumi: I also... Had a crush on you as well!

This make Ryuji shocked that he is finally succeed that she is like him and he is so happy that she also love him the same thing.

Ryuji: EH!? You are!? *Surprised*

Kasumi: Hai! I have a crush on you, Ryuji-Kun! I also planning to confess my feelings to you as well!

Ryuji: Really!? *Happy* Soo that's mean... Will you be my Girlfriend, Kasumi. I promise I will make you happy!

Kasumi: Hai! Of course!

Ryuji: YOSHA!!!

Ryuji hugged Kasumi as she blushed to see Ryuji hugging her because the ship was sailing when they fell in love like a couple.

Kasumi: Whoa, Ryuji-Kun?

Ryuji: Thank you for being my girlfriend! *Smile*

Kasumi: Mou, Ryuji-Kun. *Chuckle then hug back*

This makes three classmates drop their jaws in shocked while Saito and Utaha smirk. The three classmates were shocked to see they become a couple.

All 3 Classmates: *Jawdropped* EHHHHHH?!

Saito: Call it. Look like we win the bet.

Utaha: Yep but looks like mine is higher. *Smirk*

Then Saito and Utaha arrive as they walk down from the classroom and smirk at Ryuji and Kasumi. Ryuji and Kasumi stare at them as they are happy and smile.

Ryuji: Yo Saito and Shirashi-San! We officially now a couple.

Kasumi: Yeah! I'm glad your advice was right, Utaha-Senpai!

Saito: Congrat for you two. I always knew and believed you will success. Ryuji.

Utaha: I agree. I knew you finally confessed to him, Kasumi-Chan.

Ryuji: Yep! I never thought Kasumi had a crush on me as well. I was surprised *Laugh nervously*

Kasumi: Mou! I can't believe you didn't know even you have a crush on me!

Saito: Wow, both of you are Ten Billion Percent dumbasses for not knowing eachother feeling back then.

Ryuji: *Angry* WHO ARE YOU CALL DUMBASS, HUH?!

Saito: *Annoyed looks* You are dumbass, that's why.

Ryuji: Oi, who are you calling a dumbass!? You dumbass! *Start bickering with Saito*

Both Girls: *Sigh* Here we go again...

Utaha: Our boyfriends never changed...

Kasumi: Yep... Same old Ryuji-Kun and Saito-Kun.

This makes Saito have a crazy grin which Utaha, Ryuji, and Kasumi notice. Saito got a crazy idea for his science experiment.

Ryuji: S-Saito!?

Kasumi: W-Why are you smiling like that?!

Utaha: Hoh~ Look like he's just got something.

Saito: Hahahahahahahaha!!!! I just think of some great idea for my next experiment! *Laughing like a maniac*

Saito has an evil smile and laughing like a crazy scientist when they give him an idea for the next experiment which it is crazy.

This freaking out Ryuji because how insane Saito is while Kasumi and Utaha sigh and knew Saito always do that.

Saito: Yep, this is the best!

Ryuji: Oh my god, calm down you crazy nut job! You're freaking me out!

Kasumi: *Chuckle* There he's goes again, same old Saito-Kun.

Utaha: Hai... C'mon let's head back to class. Break time over.

They head back to the class but they don't know that someone is watching them from far away, a certain king and a certain genius watch them as a certain king sweatdrops to see how insane Saito.

??? 1: Oh boy... *Sweatdrop* Are you sure you want to choose this one as your Successor, Sento-San?

??? 2: *Grin* Of course. He is just like me but way more insane than I am! I love this kid!

??? 1: I see... Anyway, we should wait for his school time to over.

??? 2: Yep, also do you have my Build Ridewatch, Sougo?

??? 1: Yes I do. *Pull out a certain red & blue watch device*

The King took out a red and blue Ridewatch he looked at the watch and the scientist looked at the watch and knew it had the power of Kamen Rider Build.

??? 1: Here, you hold it until give it to your Successor, Sento-San. *Give ??? 2 the watch device*

??? 2: *Grab the watch device* Got it. And I can see Saito's friend is a dumb idiot just like Banjou. *Annoyed tone*

??? 1: Those two are really reminded me of you and Banjou-San, except that your potential Successor had a girlfriend.

??? 2: A-AGH! *Got hit by emotional damage arrow* Ugh... I hate it when I don't have a girlfriend! Wish the Author didn't delete my original book last year!

The watch that the scientist holding reveals it was a red and blue masked hero with Rabbit and Tank eyes. This is Kamen Rider Build Ridewatch.

The King look around as he notice some people walking by and decide that his friend to get out because they mistook them for the actors.

??? 1: Okay, let's go or before people gonna mistaken us as the Actors. We will wait for the right moment soon.

??? 2: Got it. And beside, they gonna be shock to see us as real life Kamen Rider actors.

??? 1: Yep. I do like Okuno Sou as the name tho.

??? 2: And I like Inukai Atshiro as the name. *Look at the Readers* Well then, everyone. We better see them in the timeskip!

This makes the king confused and surprised about what the scientist doing before he shrugs when he learn from his senior before they walk away.

Timeskip. After School.

Saito and Ryuji were leaving the school and taking a break, they were talking about Marvel shows and movies. Ryuji talking to Saito about the new Marvel movie.

Ryuji: Dude. Did you heard that Marvel release another trailer for Deadpool & Wolverine?

Saito: I heard, can't for it tho. The MCU been lost it touch alot since Endgame.

Ryuji: Dude! You gotta trust me and watch it! This trailer is insane!

Saito: Alright alright, no need to rush me. Big Oaf.

Ryuji opened his phone and press YouTube app before showing him the video of Deadpool & Wolverine Movie as Saito was curious about the trailer.

Ryuji: Look! They even got Tyler Mane back as Sabretooth! Took them like 24 years to give Tyler a single line of dialogue.

Saito: I supposed you have a good point. I'm quite curious about the rumor of Lady Deadpool.

Ryuji: Same, hope it Blake Livey aka Ryan wife.

Saito: I agree. Let's go watch the trailer.

Ryuji presses the video and shows the trailer video about Wolverine and Deadpool as they see the title Marvel Studio Name in the background.

https://youtu.be/r3LisZEIK34

This makes Saito and Ryuji excited to see Wolverine and Deadpool movie. They want to see it for real even Logan actor is back for real.

Ryuji: OH YEAHHH!!! *Grab Saito before hugging him until crushing his body* HUGH JACKMAN IS BACK AS THE GOAT WOLVERINE!

Saito: *Yell in pain* YOU DUMB BIG OAF! I-I'M GONNA- *Pass out and see his soul come out*

Ryuji: Oh no, Saito! Are you oka- *Got kicked in the face by Saito* AGH!

Saito: Nevermind the Movie, Idiot Big Oaf! YOU ALMOST CRUSHED MY WHOLE ENTIRE BODY! DO YOU HAVE A DEATH WISH!? *Pissed off*

Ryuji: OW! I'M SORRY!

Saito: Damn you... *Look at the Readers* My dumbass friend really based on Taiju from Dr. Stone. Am I right, dear Readers?

Ryuji: *Confused* Bro... Who are you talking to, dude?

Meanwhile, Kasumi and Utaha watching Zenless Zone Zero trailer as they watching the trailer about the characters and the games.

Kasumi: This new game from Hoyoverse is soo good, I like Ellen as my main now.

Utaha: Yeah, one of my Club Member recommended me to play this. Maybe I'll try it at home later.

Kasumi: Me too! I love Belle, she is so cute!

Ryuji: Hey you two! I see both of you are watching Zenless Zone Zero huh?

Kasumi: Yep! I can't wait to play Ellen!

Ryuji: Yeah me too! Also the new Deadpool & Wolverine Movie as well, anyway let's go for a date, Kasumi. *Smiles*

Saito: Hoh~? Asking her out already huh, Ryuji?

Ryuji: Yep! I did! I don't want to ruin my chance, you know.

Saito: Okay, good luck on your first date. Dude.

Utaha: Same here, good luck on your date as well, Kasumi-Chan.

Ryuji: Don't worry, we will! *Grin*

Kasumi: We will be fine, we promise. *Smile*

Ryuji and Kasumi leave for their first date as Saito and Utaha smile that they finally dating and happy for them. Utaha smiles as she looks at Saito.

Saito: Welp, look like there only two of us left. Wanna come to my place? I just built a interesting gadget at my home garage.

Utaha: *Smile* Sure, why not.

Saito: Alright, let's go then.

Utaha: Hai, Saito-Kun~

They holding hands together and go back to their home and start talking about their favorite science moment and invention that Utaha made.

Utaha: Saito-Kun, I got a question for you

Saito: What's it is, Uta?

Utaha: Is your Father came back from the USA trip?

Saito: Oh right, my old man say he will be back in next month.

Utaha: Souka, anyway. What career you want to pick when we graduated, hmm?

Saito: I think I gonna be... a Scientist to make a love and peace like what Sento did!

Utaha: Naruhodo, that's a great choice you have, then mine is Engineer. To create inventions to help people like you.

Saito: *Smile* That's nice! How about we work together for love and peace?

Utaha: That's a big yes! I won't disappoint!

Saito: I know you won't. You're Utaha Shirais- *Hear a sound* Huh?

Then suddenly in front of them was a portal which surprising Saito and Utaha, they wonder how did the portal get here.

Utaha: Nanja kore da?! A portal???

Saito: Hoh... Now this is intriguing... A portal appears in front of us. I thought the multiverse theory is a fiction but it's real!

Utaha: That's interes- *Suddenly got sucked in by the Portal* HYAAAAAAA!!!

Saito: UTA! Hang on! *Grab Utaha's hand and hold at the lamp pole* I can't hold it much longer!

Saito grab Utaha but he accidentally slipped his foot and suck inside the portal with Utaha as they both scream in fear before Saito look at the reader with a anger look before he's shout "ISEKAI SUCK!".

At Somewhere...

In the black void, Saito and Utaha land in the dark void, they groan before looking around the void and are confused about where they are.

Saito: Where the hell are we!?

Utaha: Um Saito-Kun, we got Isekai for some reason.

Saito: Oh god... Not this generic Isekai type craps again... I HATE ISEKAI!

Utaha: Please calm down. I know you hate Isekai but I think we should find a way to get out of here.

Saito: Ugh... I guess you're right. But we are in the void...

Utaha: Hmm... Let's me goes check around to see is there any ways to get out.

Saito: We could try but here is the problem. Who could summon us in the first place?

Saito starts muttering about theory and how did he end up summoned by someone else. He is muttering like Izuku Midoriya from My Hero Academia.

Saito: *Muttering* It either the Goddess from Isekai Anime or any entity like Tsukasa Kadoya from Kamen Rider Decade or Kami-Sama from Zenkaiger.

The scene shows the doodle art drawing of the Goddess, Kamen Rider Decade, or Kami-Sama from Zenkaiger appear and grant the person power.

Saito: *Muttering* Maybe it was Ohma Zi-O since he is the powerful Heisei Kamen Rider wielding the power of time and space. He must be the one who summons me from the portal.

Saito make art doodle drawing of Kamen Rider Ohma Zi-O from the future summon Saito and give him the power of Kamen Rider that he wanted.

Saito: *Muttering* Then he gonna send me to the world of Anime like My Hero Academia or RWBY which I don't like it at all. I prefer Honkai Impact 3rd!

Saito make art doodle drawing of being himself and Utaha send to the world of MHA or RWBY or Honkai Impact 3rd but he want to make Otto Apocalypse suffer.

Saito: *Muttering* There gotta be to get out of the place and I need t- *Got interrupted by Utaha*

Utaha: Saito-Kun... Are you done?

Saito: *Stop and has embarrassed looks* I'm done, Utaha. Sorry for muttering.

Utaha: Also why are you using Tokusatsu, Animes and Games are examples for your theories? You know it's all fictional right?

Saito: *Sigh* And we do know they are real outside our world because of multiverse theory. Why did you think I spend to read Wattpad Fanfictions and science books?

???: That's is true, Saito Kirisu.

Both: Huh? Who's there?!

Then suddenly a portal appeared and someone came out the person smiled which shocked Saito and Utaha that he saw a familiar person from another world.

???: Interesting theory you made here, Saito Kirisu. You are correct about the last two.

Saito: N-No way!? You're?!

???: Yep that right, the one and only. The greatest, kindest Demon King!

The scene shows a brown hair young man wearing a yellow shirt, and his waist has a certain Driver as he holds his finger in a pose. This is Sougo Tokiwa aka Kamen Rider Zi-O.

Sougo Tokiwa aka Kamen Rider Zi-O! The Demon King Of Time! IWAE!!!

This make Saito and Utaha shocked that they encounter Sougo Tokiwa from Kamen Rider Zi-O show, the greatest kindest demon king that they meet.

Sougo: Nice to meet you, Saito Kirisu.

Saito: It's Sougo Tokiwa! I didn't know you are exist!

Sougo: It's a long story. Let's just say... I am really real because fiction are real and existed in the multiverse.

Saito: I knew it! Multiverse theory is exist!

Utaha: Yeah! Can't believe it actually true!

Sougo: Indeed, and we here for you, Saito-San. There someone who want to meet you.

Saito: Eh? Who?

???: That's would be me! *Excited tone before hair pop up*

The scientist appear as Saito was shocked and excited to see his favorite hero is here to introduce him, the scientist smile and glad to see his successor.

Saito: EH?! S-Sento!?

???: That's right! Sento Kiryu the Rider of Love and Peace! *Doing his pose*

The scene show a black hair man with his excited look and his hair poked out. This is Sento Kiryu the Genius Rider, the Kamen Rider Build and the Rider of Love and Peace.

Sento Kiryu aka Kamen Rider Build! The Genius Hero! Best Heisei Kamen Rider! BEST MATCH!

This make Saito drop his jaws in shocked to see Sento Kiryu who is a real in front of him while Utaha shock to see Sento Kiryu is real.

Sento: I know, surprised isn't it?

Saito: Y-Yeah! You are real! I guess the multiverse theory is true!

Sento: Yep, and I come for you to chosen you to be next Kamen Rider Build.

Saito: ...Eh? EEEEEEEEEEEEEEHHHHHHHHHHHHHH?!

Saito was shocked that he was chosen as Kamen Rider Build by Sento. Sento chuckle to see the reaction of Saito that he chosen as the next Kamen Rider.

Saito: M-Me!? You're choosing me as the next Kamen Rider Build!?

Utaha: Uso!? My boyfriend becoming a Kamen Rider!?

Sento: That's right! You are official Kamen Rider Build!

Saito: TEN BILLION PERCENT SAIKOU DA! *Excited tone*

Sento: I KNOW RIGHT?! *Excited tone*

Saito: Also Sento-San I got a question, why do you choose me to take your mantle as next Build?

Sento: *Frown in serious* Because Faust are back.

Saito: Wait what?! Faust?!

Sento shows the hologram of Neo Faust lead by the red spider Kamen Rider alongside robot soldiers army who attack the city in burning background.

Saito: Nani?! Killbus back?! He's also rebuilted Faust and renamed it to Neo Faust. How that possible!?

Sougo: That's why we're investigating it. We have no idea how he came back.

Sento: That's right. And I need a Successor to take the mantle since I retired.

Saito: Oh that makes sense. But how do I get to their world?

Utaha: I agreed.

Sento: I'll tell you later, but first. I think you need this. *Give Saito the Ridewatch*

Saito: Is that... The Build Ridewatch?

Sento gives Saito a Build Ridewatch which confuses Saito and Utaha, usually, the Rider gives them the Driver and their transformation item.

Saito: Build Ridewatch? I don't understand, why giving me a Ridewatch instead of actual Build Driver?

Sento: Simple. The Build Ridewatch holds my powers and Build Driver so you can summon it and it will give you the power of Build.

Saito: Naruhodo, I forgot Ridewatch can do that.

Sento: Yep, anyway why don't you tried to activate it?

Saito looks at Kamen Rider Build Ridewatch Utaha worries about what's happened to Saito as Saito decides to activate Kamen Rider Build Ridewatch.

Saito: Heh... Guess I should try. *Smirk*

Utaha: Saito-Kun.... *Worry tone*

Saito: Alright, here we goes! *Smirk*

Saito presses Kamen Rider Build Ridewatch which announcement the song and says the words from the watch device.

*Digital beeping*
BUILD!

Then the watch annoucement second sound line as it says the history of Kamen Rider Build and the clock is ticking.

Best Match! Fullbottle de henshin-suru tensai Rider wa...
*Clock ticking noise*
BUILD!

Saito was confused before a red and blue energy line formed on Saito's waist which surprised Saito and Utaha as they see the energy line form a belt.

Saito: This is...?

The driver has a crank level, two slot on the side, and it has a gears on it. This is Build Driver the main Driver of Kamen Rider Build.

He was surprising to see Build Driver is a real in his waist, while Utaha has star eyes want to touch Build Driver because she love the driver's gear.

Saito: AWESOME! I GOT BUILD DRIVER ON MY WAIST! IT FEEL LIKE A REAL DEAL!

Utaha: Amazing! What a real gear! I love it!

Saito: I know righ- *Noticed Build Ridewatch changing* Huh?

Then the Kamen Rider Build Ridewatch changed into an two colorful bottles, revealing it was Rabbit and Tank Fullbottles, aka Kamen Rider Build's transformation item.

Making Saito excited to see his favorite Fullbottle become real and look at Fullbottle while Utaha has star eyes look at the Fullbottles.

Saito: Oh hell yeah! My Fullbottles! Best Match!

Utaha: Rabbit and Tank are good choice!

Sento: Of course, it's a classic Base Form for Build. Anyway we're gonna send you two to the Universe were Neo Faust plotting in now.

Saito: Huh? Which World you two gonna send us now?

Sougo: The Marvel Universe.

Utaha: Eh?

Saito: HEEEEEHHHHHH?! *Make a stupid shocked face*

Saito makes a stupid shocked face like what Senku did in the show as he was shocked that he going to the world of Marvel

Saito and Utaha were shocked that they going to the world of the Marvel Comic Universe while Sougo and Sento chuckle when they see the successor's reaction.

Saito: Say what?! I'm going to Marvel Comic Universe!?

Utaha: Uso darou?! Is this real?

Sougo: Of course it's real and that's why Neo Faust is hide in the world of Marvel.

Saito: This is the best! I can't wait to meet the man in Iron Suit himself, Tony Stark aka Iron Man! He's my favourited Hero!

Utaha: I want to meet Iron Man and War Machine! His tech suit is amazing!

Saito: Other Marvel Heroes too as well! Especially Spider-Man!

Saito and Utaha were excited to go world of Marvel Comic and Utaha decide to be Saito's assistant for Science and Engineering.

Utaha: Hey Saito-Kun, can I be your Assistant? Like I will help you created some gadgets for you as Kamen Rider Build to help the Avengers and other Heroes.

Saito: *Grin* Of course you can!

Utaha: Awesome. Technology Advantage is what determines its victory!

Saito: Damn right!

Sougo summoned a portal as Saito and Utaha were ready to go inside the portal and they looked at Sougo and Sento to say goodbye.

Sougo: You two ready?

Sento: I hope you ready for your journey, my successor.

Saito: Hehehe. *Chuckle* Sento-San. Ten Billion Percent I will succeeded you as the next Kamen Rider Build.

Sento chuckled and liked what Saito saying. Seito silent as he smirks and decide to success in what Sento did as Kamen Rider Build.

Saito: This is Exhilarating! *Smirk like Senku*

Saito and Utaha went inside the portal before the portal closing and Saito and Utaha flew inside the dimension wormhole. Ending the chapter.

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To Be Continued.