Fate/Stay Night and Kyuu Kara Maou Crossover

Title: An Experiment Gone Wrong- New Heroes of the Kingdom

Prologue: Anissina's Portal

"Your majesty! Your majesty!"

Yuuri was running around the corner of the corridor, preventing himself from being caught by the enthusiastic Anissina. There was no need to guess what was happening.

Anissina had just invented a new device called 'The Portal' which allowed anyone to move from one portal to another. And since Gwendal and Victor were on a Diplomatic Trip, there left only one person Anissina could test her invention on, Yuuri.

Alas, Yuuri was not a good runner, so he got caught by Anissina. Even being caught firmly by Anissina, Yuuri struggled to escape as he knew the results of Anissina's inventions. Utter failures.

The last time Victor had to use all of his strength to pedal the bicycle so that Anissina's television could work. And the television exploded when it was finally turned on.

"Your majesty, why don't you try my new invention. It is very neat. It is called 'The Portal'. Do not worry, for I will test it with something. Ah… a banana skin."

Anissina pressed a button in her laboratory and the two portals powered up, giving a sense of chilliness to the King. Then, she took the banana skin and threw it in.

They waited for the skin to come out.

They waited. They waited…

Yuuri broke the silence. "So looks like it does not work. Well, let me get back to sword-training with…"

"Woah…" came a sound from the Portal.

"Yikes!" Yuuri cried out as a young blonde woman slid out of the portal, followed by a red-haired boy, followed by a purple-haired girl, followed by a smaller girl with white hair, behind them, a middle-aged guy with white hair and red shirt, together with a girl in red shirt and lastly, a woman with spectacles and long purple hair.

To get to the point, they made a mess of the laboratory.

The blonde woman got up first, "Wait…where am I?"

She looked around her surroundings. It was very medieval, like her old home. But something was not quite right. Two nice gigantic machines and one humungous keyboard?

She immediately changed into battle armour and pointed her sword towards the maou.

Yuuri made a scared sound. "A…Anissina…WHO ARE THEY?" He yelled before running around the room as though Anissina was chasing him, this time, it was the blonde girl, shouting, "I demand an explanation why we were summoned here."

And then, Yuuri stood there, looking like an idiot, sighing in relief, "At least they are not hostile…"

All the others stood up. "Hey, where in the world are we?" The red-haired boy asked.

"This is the wonderful Demon kingdom, I am their King…"

"Demons?" The blonde girl held up her blade and was prepared to strike.

Yuuri rolled to the side before the blonde girl dropped the blade. She missed, and the blade sliced through the mother keyboard like a hot knife on butter.

"Saber, that is enough," the red-haired boy shouted before approaching the blonde girl.

"But…Shiro, they are demons…"

"Demons may they be, they might not be as cruel as you think."

"Fine."

The blonde girl put the sword back into the sheath.

And Anissina was left standing there, looking at the mother keyboard or that sort of thing.

"It's…ruined!!"

"So it looks like we cannot return home, then." The white-haired guy said.

"Why are you saying it so calmly, Archer," the girl in red shirt said before whacking her servant's head with her hands.

Conrad arrived at the room and saw the whole mess and the strangers.

"Wait, what is going on here?" he said.

"Just another of my inventions," Anissina answered.

Then, the maou stood up and said, "Wait, are you guys from Japan, back at the human world?"

"Yes," the boy with red-hair, supposedly known as Shiro, replied.

"So what happened, at Japan?"

"Well…

" 'Hey! Give me back my meatballs!' Fuji-nee was shouting. It seemed that Saber here stole her meatballs. They were running around the house, one escaping from the other. And then, Saber was running around a corner when a banana peel came out from nowhere and she slipped and into the wall, which was supposedly a portal.

"Then, she disappeared into the portal, and I tried to pull her back. However, the portal seems to have a lot of power, and sucked me in, together with the other five of them behind me."

"Wow, that is surely a mess," Yuuri commented.

"And what happened here?" Saber asked.

"Well…

"Anissina here had a new invention called 'The Portal' which supposedly could teleport someone from Portal A to B. She wanted me to test it out. To prevent me from going into 'somewhere', she tested it and threw the banana peel inside. And that is what happened here."

"A portal to our world, huh? Your friend has a nice invention, especially at such times…" Archer said before receiving another whack on the head by the red shirt girl.

"Well, let us introduce ourselves then," Yuuri said, "I am Yuuri Shibuya, Demon King, this lady here is Anissina, the head of the palace maids, however, she is an inventor. Most of the times, her inventions are screwed up."

"Hey!"

"And here is my godfather, Conrad. Well, he actually so called made me born in the human world, so…"

Shiro continued, "I am Shiro Emiya and the girl beside me is Saber."

Archer interrupted, "She is good in sword fights…Oww…"

Another whack from the red shirt girl.

Conrad requested, "I see. May I recommend a fair duel, lady?"

Saber nodded.

The girl with the red shirt spoke, "I am Rin Tohsaka, and the idiot that I had whacked three times is Archer."

The purple-haired girl spoke, "I am Sakura Maotou, and the girl beside me is Ilya. And she is Rider." Sakura pointed at the woman wearing spectacles.

The woman added, "Don't call me Rider. Just call me Medusa, Demon King."

"Ugh…Medusa? Then how is it that I am not stone now?" Yuuri asked.

Rider pointed at her spectacles.

"Jinxed," she said. Yuuri nodded.

Saber abruptly left the room. "Come, Conrad. Didn't you say you wanted a duel?"

Conrad smiled. "Glad you remember."

OMAKE- Something that happened right after that scene…

What Anissina said just before everyone went to the sword fight…

"Oh no! My invention…my hard work…it is ruined!! I had been developing that thing for a month! (Sudden breakdown) Now I have to fix it!"

And everyone turned around, saying, "WWHHHHHHHHHAAAAATTTTTTTTT?"

Yuuri asked, "How long would it take?"

Anissina replied sadly, "At least a month."

Everyone could not believe it.

"So we are stuck here for good," Archer said before receiving a fourth whack on the head.

"Didn't I say that you should not be rude, Archer?" Rin said, showing a nearly exploded vein on her forehead. Smoke was gushing out of her ears.