"Is that all you need?" the clerk behind the counter asked.

"Yeah. This is all I need," Shirou replied.

"Okay. Your total amount is 1,000,000 QP." Shirou then handed the clerk 1,000,000 QP. "Thank you. Have a nice day and we hope you can come back another time," the clerk said with a smile.

"Yeah. See you." Shirou then left the shop, carrying all the items he bought earlier.

Which were carbon resin, and parts of a small engine.

Shirou let out a small sigh as he looked at the parts and carbon resin. "I can't believe Da Vinci is actually going to make this..." Shirou thought as his mind went back to an earlier time...

(A while ago...)

"Huh? You want to build what?" Shirou asked, surprised at the item Da Vinci want to create.

"You heard me Shirou. I want to build a hoverboard. And not the ones that has wheels! I'm talking about the real ones that float in the air!" Da Vinci yelled excitedly.

Shirou was flabbergasted at what Da Vinci just said. "So...what made you come up with this idea..." he asked.

"Well...let's just say I've been watching too many old classic movies these days...and there was this one movie that piqued my interest..."

At that moment, Shirou had a guess of which movie Da Vinci was talking about. "Let me guess. You've seen the movie, "Back to the Future," didn't you?"

"Yup...and its sequels as well. Does Back to the Future exists in your world as well?"

Shirou nodded in reply. "It was pretty popular at the time of its release. Even spread through other countries as well."

"I see. Anyways, because of that movie and its sequels and the inventions, I wanted to create one of them."

"Is that so? But do you even know how to build a hoverboard? I mean, the movie does not show the blueprints on how to make one."

Da Vinci let out a smile. "Don't worry! I can figure something like that! After all, I'm Da Vinci, the greatest genius that has ever lived! In fact, I've already made the blueprints for it already!"

Shirou's eyes grew. "Really?"

"Yeah!" Da Vinci then headed towards her table and grabbed a giant piece of paper. "Here!" she said as she presented the giant piece of paper in front of him.

As Shirou looked at the giant piece of paper, he was amazed. In front of him was a blueprint of a design of a hoverboard. In the blueprint were parts of the hoverboard, the schematics telling which part is which and where the parts go on the hoverboard.

"Wow. She really did make the blueprints for it."

"See? I told you I made the blueprints already!" Da Vinci said proudly.

"You sure did..." Shirou said.

"Anyways. I need you to get these materials for me," Da Vinci said as she handed Shirou another piece of paper. This time, the paper was a list of materials needed to make the hoverboard.

"You want me to get these?" Shirou asked.

"Yes. Can you?"

"Well, I can, but-"

"Excellent! Now hurry up! And don't come back until you got the parts that I need!" she said as she then pushed Shirou out of her workshop, leaving Shirou baffled as what just happened.

"Wow...Da Vinci really wants to create this..."

(Back to the present...)

"Even now, I still can't believe that Da Vinci actually wanted to make a hoverboard, even though she's already created so many experiments and inventions that would cause a lot of copyright infringement that would cause Chaldea to have multiple lawsuits coming..." Shirou thought as he carried the parts back to Da Vinci's workshop. Eventually, he arrived at Da Vinci's workshop. "Da Vinci. It's me, Shirou. I've got the parts that you wanted."

In an instant, the door quickly opened, revealing Da Vinci, who had a huge smile on her face. "All right! Come on in!"

Shirou then went into Da Vinci's workshop, where he placed the parts he bought on a table. Da Vinci then examined the parts Shirou bought.

"Well?" Shirou asked.

Da Vinci's smile grew even further. "It's great. Now all I need is to apply all of them together! Now if you will excuse me, I need a few days to complete the hoverboard, so don't bother me for a while Shirou!" she said as she soon began to start her work on the hoverboard.

As Da Vinci focused herself into her work, Shirou couldn't help but feel scared of her for some reason...

A few days has passed since Shirou brough the materials needed to make the hoverboard Da Vinci was created, and ever since then, she hasn't left her workshop.

And it was starting to worry some people, especially Romani.

Right now, Shirou and Romani were walking down the hallway, heading towards Da Vinci's workshop.

"Are you sure that Da Vinci is okay?" Romani asked.

"Yeah. She told me to not bother her when she's working on the hoverboard. And it's been a few days not since I've ever heard from her. Maybe she's still working on it," Shirou replied.

"I see. Still though, this is the first time I've ever seen her like this...I guess my death affected her..."

Shirou let out a chuckle. "Relax. This isn't an effect of your supposed death. Rather, it's because she was busy and watched so many shows and movies in Chaldea's broadcasting system."

Romani let out a small sigh of relief. "Well, that's good. By the way, how is it being Da Vinci's helper?"

"Well...let's just say, it's quite the experience for me," Shirou said with a sigh in the end.

Romani then placed a hand on Shirou's shoulder. "Tiring, isn't it?"

"And crazy." Eventually, Shirou and Romani arrived at the front door of Da Vinci's workshop. "Well, here we are." Shirou then knocked on the door. "Da Vinci! It's me, Shirou! And I brought Romani with me!"

There was no response.

"Da Vinci?" Romani asked.

Then in an instant, the door opened, revealing Da Vinci who looked like she didn't get any sleep due to the bags under her bloodshot eyes. "Hey there...Shirou...Romani..." she groaned.

"Da Vinci...you don't look so good..." Romani said.

"Well...this is the price...for creating a hoverboard overnight...without any sleep...anyway, come on in," she groaned as she introduced both Shirou and Romani into her workshop. As they went into her workshop, both Shirou and Romani were surprised at the mess she made in her workshop.

Especially Romani since it's been a while since he visited her room.

"Wow. Da Vinci's room in even more of a mess than the last time I've been here. And it seems like she's been really busy..." Romani thought as he looked at the massive number of inventions Da Vinci made over the years.

Eventually, Da Vinci stopped at a table, which had a hoverboard. Both Shirou and Romani were amazed with what Da Vinci just created within a few days.

"Da Vinci...is this the hoverboard you were talking about?" Romani asked.

"Yeah...impressive, isn't it?" Da Vinci replied.

"Impressive?! I'm completely shocked! How did you manage to recreate the hoverboard from the movie, "Back to the Future 2?!" There were no blueprints whatsoever in the movie! How did you do it?!"

Da Vinci let out a chuckle. "Simple...trial and error..."

Shirou then grabbed the hoverboard and inspected it. "Does it work Da Vinci?"

"Heh...yeah, it hovers all right...all that's left is for you to test it out...since you're the one who brought me the parts...after all..." Da Vinci muttered before passed out from exhaustion.

Romani let out a small sigh. "Da Vinci...you overworked yourself again," he said as he began to pick her up like how a gentleman would. "Anyways, I'll be taking care of Da Vinci now. You go on ahead and test out the hoverboard."

"You sure?"

"Yeah."

"I see. Well then, I guess I'll be on my way now. See you Romani."

"See you Shirou."

Shirou then left the room, leaving Romani alone with Da Vinci...

"Now then. How do I make the hoverboard work...? From what I know, in the movie, the main character used it by getting on it, but does it start up? Is there some kind of sensor on there or something? Or is there a switch...man, I wish Da Vinci could have at least gave me instructions on how to use it before she passed out..." Shirou thought as he examined it.

As Shirou continued to examine it, it was then a certain servant stopped by.

"Shirou, what are you doing?" the servant said.

Shirou looked to see who was the voice. It was Archer Arturia.

"Oh. Hey there Arturia, I'm having a hard time trying to figure this out..." Shirou replied.

Archer Arturia then looked at the hoverboard Shirou was inspecting. "That? What is that? It looks like a surfboard."

"Well, this is a hoverboard from an old classic movie called, "Back to the Future." For the past few minutes, I've been trying to figure out to start this up."

"I see, but why do you have it?"

Shirou let out a small sigh. "Well, for the past few days without any sleep, Da Vinci has been making this hoverboard because of the movie I mentioned earlier. And right now, she wants me to test it, but the problem is that she didn't give me any instructions on how to use it."

"Oh. Well...do you mind if I take a look at it?"

"Sure. Here," he said as he gave Archer Arturia the hoverboard. Soon, Archer Arturia began to inspect the hoverboard like Shirou did earlier. "Hm...I think I know how to get the hoverboard started."

"Really? How?"

"Well, this is probably a guess, but I think it automatically activates when you stand on it. Try it out and see." Following Archer Arturia's words, Shirou then took the hoverboard and placed his feet on it. As he did, the hoverboard activated by itself, making Shirou hover over the ground along with itself.

"Wow. You were right Arturia," Shirou said as he was in wonder.

Archer Arturia let out a smile. "See?"

As Shirou was on the hoverboard, it was then he was hit with an immediate problem. When he turned his body around, he suddenly lost balance and was struggling to stay on the hoverboard. Eventually, he then fell from the hoverboard, but Archer Arturia managed to catch him in time.

"Are you all right Shirou?" Archer Arturia asked.

"Yeah. It seems that it's going to take some time using it..." Shirou replied as the hoverboard slowly powered down, falling to the ground gently.

"You can say that..." Archer Arturia said. As she looked at the hoverboard, a thought came into her head. "Hey Shirou, Da Vinci did say that she needs feedback on the hoverboard, right?"

"Yeah. Why?"

Archer Arturia let out a smile. "Well...how about I teach you how to use it?"

Shirou was surprised for a moment. "Eh?"

"You didn't hear me? I want to teach you how to use the hoverboard. Da Vinci did ask you to get some feedback from testing the hoverboard, so I figured I might help you with it."

Shirou was speechless for a moment. "How can you help me use the hoverboard?"

"Well...I know how to use a surfboard. Being on it is the same thing as being on a hoverboard, so I think I can help you with that."

"Are you sure?"

"Yes. Anyways, you need some help or not?" Archer Arturia asked with a pout on her face.

In an instant, Shirou immediately felt weak upon seeing Arturia's pouting face. "Whoa. That's a new face..." he thought as he was trying to control himself.

After a few minutes of getting himself back under control, he had his answer. "Well, you have a good point here. Da Vinci needs feedback, guess I'll need your help."

Archer Arturia let out a smile. "Great! Let's go then!" she said as she grabbed Shirou's arm and started dragging him in the hallway. Soon, Archer Arturia and Shirou arrived in Chaldea's testing room. "All right. Shall we begin the experiment?"

"Yeah," Shirou said as he went on the hoverboard. As he did, it automatically started floating in the air, only by a few feet from the ground. "All right. What do I do now?"

"Maintain your balance by putting your left foot forward your right foot," Archer Arturia said. Shirou then did what Archer Arturia said. "Good. In that position, you're going to push with your right foot and ride with your left. Now try to push off."

Shirou then pushed with his right foot, and he was moving slightly away from Archer Arturia. "Like this?"

Archer Arturia let out a smile. "Good! Now, try to shift into the riding position. When you get moving, you need to shift your riding foot sideways and bring your pushing foot up to rest lightly at the back of the board. Your knees should be slightly bent, but you should be generally standing upright, with a straight back, to learn to balance correctly.

Shirou then followed Archer Arturia's directions. "Great. Now we're going to learn how to turn. Are you ready?"

"Yeah."

"Good. Now, in order to turn, shift your weight forward or back from the ankle, depending on your stance and whether or not you want to go right or left. If you want to stop, then gradually slow down, and stop by putting a foot to the pavement. However, do it slowly just in case right now."

Shirou nodded and shifted his weight forward. As he did, he slowly shifted his body to the left, making the hoverboard moved left. Shirou then slowly shifted his body to the right, and as such, the hoverboard moved right. As the hoverboard continued moving, Shirou gradually slowed down, and stopped it by putting a foot to the pavement.

"Good! You're doing better Shirou!" Archer Arturia said with a smile on her face.

Upon hearing Archer Arturia's words, Shirou practiced more on controlling the hoverboard. Over time, he got used to the controls of the hoverboard and was able to move in any direction with ease.

"All right. This isn't bad..." Shirou thought.

"Hey Shirou! Let's take a break for today!" Archer Arturia said.

"All right!" Shirou said as he proceeded to stop the hoverboard...until something unexpected happened.

Because before Shirou could stop the hoverboard, a giant booster popped out in the back of the hoverboard, surprising Shirou and Archer Arturia.

"What the heck?!"

In an instant, the booster accelerated the hoverboard's speed, making it go out of control and forcing Shirou off.

"Shirou! Are you all right?!" Archer Arturia yelled as she went over to where Shirou was dropped.

"Y-Yeah..." Shirou replied before he noticed the out-of-control hoverboard heading towards the two. "Look out!" he yelled as he pushed Archer Arturia out of harm's way.

In an instant, the out-of-control hoverboard went past Shirou and Archer Arturia and crashed into a wall, breaking the hoverboard into two.

"Wow...what just happened..." Archer Arturia muttered as she was in shock of what just happened.

"I don't know, but one thing for sure...that was not in the movie..." Shirou replied.

As so, Shirou and Archer Arturia gave Da Vinci the feedback on the hoverboard later when Da Vinci recovered...

Little did they know that Da Vinci had a plan for the hoverboard...

Omake

Shirou was walking down the hallway, minding his own business. As he did, he came across a poster that completely made him dumbfounded.

The poster was a promotional advertisement of hoverboards, and they were made by Da Vinci.

Shirou mentally groaned upon seeing the poster. "Da Vinci...what have you done..."