What happens when you summon Emiya Shirou in Chaldea

Hoverboard

"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."