Twilight and Whisper walked out of the castle and into the market to try and find any witnesses for their case. They had all of the fundamentals that they needed to get some leverage in their case, but without stronger proof, they were just clutching at straws with no clear indication of what was really going on.

"There are an awful lot of ponies in Ponyville." Twilight looked around and saw the crowds going about their daily routines. "One of them must've seen Rarity and the Boss Yo-kai who inspirited her last night."

"Yes. But the real question now, is who?" Whisper flew on ahead and looked at each and every pony as close as he could, mainly at their eyes and their faces. "I'm pretty sure that the whole town must've been fast asleep when Rarity was spirited away, so there's not really many shots we have at this."

"If Rarity went out with a Boss Yo-kai, then they can't have been completely quiet about it, right?" Twilight saw Whisper float right back to her. "Somepony, at some point in the evening, must've somehow heard the noise that those two were causing." Twilight nodded. "If we can find that pony and ask them about it, then we might get a vital piece of the puzzle."

"Again, though. Who in Ponyville could've possibly been up that late to hear Rarity and the inspiriter?" Whisper asked. "It seems like a tough case to crack, Twilight..."

"Do you doubt me, Whisper?" Twilight picked her hat off of her head, dusted it off, and put it back on. "I happen to have an IQ of two-hundred and fifty. A number which I earned blasting through hundreds of tests at Celestia's School for Gifted Unicorns. I'm somewhat of a child prodigy." She blushed.

Whisper's mouth dropped wide open as he floated in awe at Twilight's sentence. As she walked off without him, he closed it up and tried to keep up. In all of his years, he had never seen a pony that smart before.

"Two-hundred and fifty?" Whisper repeated.

"Yes," said Twilight. "And even with that high IQ, I still can't quite figure out what could be behind this, or who could've possibly seen it."

"Well, you also have a piece of evidence in your possession." Whisper reached into Twilight's mane and pulled out the plastic bag with the white hairball in it. "Opal mentioned that Rarity coughed this up when she supposedly turned into a cat, right?"

"Yes. What significance does it have on finding someone else who could've seen her leave, though?" Twilight eyed up the evidence from all corners. The hair was clear white with nothing else stuck to it."

"If there is a Boss Yo-kai on the scene, then it's likely that it could've gone for much more ponies than just a simple dressmaker." Whisper held up the hairball in front of his face and looked at the ponies again shortly after. "Maybe, we shouldn't ask about who saw Rarity, but rather who coughed up hairballs of their coat colours. That sounds slightly easier than trying to find the one pony who stayed up way past their bed time last night."

"But even if we did ask ponies about that, what's the betting that we'll actually get one that did cough up a hairball like Rarity did?" Twilight tilted her head to the side. "It just doesn't make any sense."

"The truth is stranger than fiction, Twilight." Whisper crossed his arms. "And considering that your world has only just become infested with Yo-kai, then those truths have most likely gone up two, or maybe three notches on the strange scale. With all the things that Yo-kai can do, I wouldn't be surprised if this supposed Boss Yo-kai who turns their victims into cats would also make them cough up hairballs like real ones would."

"You're saying it might not be just Rarity who turned into a cat that evening?" Twilight cocked a brow at Whisper. "But then, who else could we talk too about it?"

It was then that Twilight bumped into the Cutie Mark Crusasders. She and the three fillies all stumbled backwards, shaking their heads to recover from the impact.

"Oh, hi, girls." Twilight looked down at the fillies with a smile on her face. "Why aren't you in class?"

"Well, actually, Twilight, we were asked to go home for the day." Scootaloo walked up to her.

Twilight put a hoof on Scootaloo's forehead to check her temperature to see if she was faking it. She felt that it was at a normal temperature before she did the same with Applebloom and Sweetie Belle, turning up the exact same results. "But you look perfectly fine to me. Why would Miss Cheerilee send you three home?"

"Well, that's actually a funny story," Applebloom meekly chuckled before she felt something in the back of her throat. "Oh no! Here comes another one!"

"Another what?" Twilight raised a brow at Applebloom as she sprawled down onto her flank and began hacking and coughing. For a second, she thought that Coughkoff had inspirited the filly.

The coughing went on for a while until Applebloom threw up a ball of yellow hair. It splatted onto the floor and rolled for a few seconds right up to Twilight's feet, causing her to yelp and jump back into the air.

"A hairball! Just like the one Rarity coughed up!" Whisper picked up the clump of hair and stuffed it into another bag that he pulled out of his body. "Well, that just proves it, Twilight. This Boss Yo-kai not only went after Rarity, but it went after these poor, sweet, innocent fillies too." He pinched their cheeks. "What a monster. Why, if I were a fighting Yo-kai, I would go right up to that ruffian and give him a pounding the likes of which you've never seen before!"

"Darn it!" Applebloom cleaned up her mouth, wiping away the remaining residue. "Yeah. Sorry about that, Twilight. Ever since this morning, we've been coughing up those hairballs like crazy."

"Uhh... Twilight?" Sweetie Belle looked up at Twilight, seeing that her eyes were hidden behind her mane.

"Girls. I need to talk with you. Right now." Twilight knelt down to the fillies. "Rarity had hairballs just like yours this morning. Something called a Yo-kai has plagued this town, and I'm not sure who could be safe from it."

"Yo-kai?" Applebloom tilted her head.

"Yo-kai are invisible creatures that live in the world around us. They take control of our bodies and make us do things that we would never expect, or even consider." Twilight showed the fillies her Yo-Kai Watch. "This device I'm wearing is the only way that we can see them. It uses a highly concentrated ultraviolet ray to uncover the Yo-kai plaguing our town. It also allows me to summon any that I've befriended into battle, should the need be."

"Yo-kai? Invisible friendly creatures?" Scootaloo let a small chuckle slip. "I've seen some weird stuff in Equestria, but invisible creatures just sounds ridiculous."

Twilight used the Yo-Kai Watch to reveal Whisper to the three fillies. He waved at them while they just stared in awe. After which, she closed the lens, letting Whisper return to being unseen.

"Now do you believe me?" Twilight asked.

"Y-yeah. Of course we do." Sweetie Belle nodded frantically. "It's just that, I'm not so sure that one of those ghosts could've made us cough up hairballs. That's a cat thing, not a pony thing."

"The Yo-kai that inspirited Rarity and you last night turned you into cats and most likely blanked your memories when you woke up." Twilight drew closer and closer to the solution to the riddle. "That's why we need to find a way to draw this Yo-kai out and take them down, no matter the cost."

"But if it turns us into cats in the middle of the night, then how in the heck are we gonna be able to capture it if those cat-like instinct take over?" Applebloom asked.

"From what we've gathered so far, this Yo-kai only tends to strike when ponies are asleep." Twilight began pacing back and forward. "We'll need a flawless way of dragging it out, but how?"

"Boss Yo-kai don't just come out when you bait them, Twilight." Whisper wagged his finger. "They come out whenever they feel like it, to serve as an oversized roadblock for our progress. You can't just trick them into inspiriting something that's not a pony, or just fight them because you feel like it."

"That's not entirely true, Whisper." Twilight looked at the Cutie Mark Crusaders, then back at Whisper. "I have a plan that'll not only prove that this Yo-kai is after the townsponies, but also give me a solid lead on where and when they'll be at night."

"How?" Whisper asked.

"The simplest of traps is also the most effective for luring out someone inspiriting multiple ponies—especially my friends." Twilight stepped in between the whole group. "We're going to have a slumber party at my castle. Then, when this evil Yo-kai shows up, we all wake up, pounce on them, and save Ponyville once again!"

"That sounds like a great idea!" Scootaloo nodded before she coughed up an orange hairball and cleared her throat. "I could even bring Rainbow Dash. She loves fighting against monsters!"

"Sounds wonderful, girls. In fact, why not have all of my friends join us?" said Twilight. "Pinkie Pie could provide the snacks; Rarity could be the the one behind makeovers; Rainbow Dash'll be there to support you, Scootaloo; and the rest could be there just for the heck of it!"

"Well, what are we waiting for then?" Sweetie Belle charged off with the other Cutie Mark Crusaders. "We've gotta prepare for the evening! We'll see you around, Twilight!" She waved back at her before they went down another road.

"A slumber party used to trap the Boss Yo-kai..." Whisper put the whole scenarion into his head. He could already imagine everyone having fun, the Yo-kai attacking when they were all asleep, and then Twilight using her watch to vanquish it. "It's an ingenious idea you've got, Twilight. But executing it might be harder than you think..."

"How so, Whisper?" Twilight walked off with a spring in her step as she went to invite the rest of her friends to the party.

"Boss Yo-kai are so formidable that one Yo-kai alone won't be able to defeat them." Whisper squinted his eyes. "More often than not, people who only fight with one at a time often tend to get destroyed by them, which is why I advise that when you fight this Boss Yo-kai, that you bring out all eight of the Yo-kai you've befriended all at once, and co-ordinate them like you would the leader of a group. Only then might you find victory."

"I'll be sure to enhance the Yo-kai Watch for tonight, then." Twilight went off into another street with Whisper floating close behind her. "You just make sure that you're ready for the party tonight."

"I'm always prepared for a party of any description." Whisper changed his clothes repeatedly every quarter of a seconds. "I've got weddings, birthdays, anniversaries, raves, conventions, and even slumber parties. Speaking of which, I hope you won't mind being at yours, seeing as I am a male Yo-kai after all..."

"It's alright, Whisper. You're a ghost, so nopony else can see you having fun tonight." Twilight nodded and stroked his belly. "Besides, I don't think I'd be able to pull this trap off without your help, so you can totally come."

"Thank you, Twilight." Whisper bowed to her. "I assure you that tonight will be a night you won't forget for a long, long time..."

Unbeknownst to Twilight, a bipedal Yo-kai with a scarf made out of two curled up dragons had been watching her from the rooftops. The Yo-kai looked identical to that of a human, with long black hair, wide orange eyes, and his mouth obscured by the scarf. The dragons themselves were whispering into the Yo-kai's ears, to which he spoke back.

"Twilight Sparkle faces against her first challenge." The Yo-kai stroked his scarf as he watched her walk away. "This Boss Yo-kai will test all of her skills she has learned so far. Fate will decide whether or not she is victorious in her efforts."

"We need her to be ready to face the future." Another Yo-kai appeared next to the first one. It was a massive bipedal fox with a golden coat, with nine tails that were coloured purple on the tips. It had facial markings and spoke in a feminine voice. "If she falters, then this world could very well succumb to the darkness."

"She has only faced eight Yo-kai thus far. We should let her face this first Boss Yo-kai so that she can have her abilities strained." The dragon scarf Yo-kai stood upright. "Only through struggling and victory, will she be one step closer to becoming the chosen one."

"The queen is looking for only the best and brightest bearer of the Yo-Kai Watch to stand up to the darkness." The fox stepped towards the edge. "Twilight Sparkle is still a mortal being, and she can still be defeated by these tyrannical creatures."

"Do you doubt her strength, Kyubi?" said the other Yo-kai. "I will admit that Twilight doesn't seem to be living up to the queen's expectations, but she does have Whisper with her. We'll just simply have to wait and see."

"Without a chosen one to defeat the king, we are nothing but cattle, Venoct." Kyubi tightened her left claw into a fist. "I have fought against many a Yo-kai before this, but against him and his dark powers, we are lucky that he hasn't staged an attack on this world, or our own. She needs to be ready now!"

"Be patient, Kyubi." Venoct threw out his arm in front of her chest. "You cannot rush fate. It comes to you when it wants to. If it decides to wait until the king declares war on Equestria and the Yo-kai World before making Twilight the chosen one, then we must abide by it's decision."

"You've been talking to that scarf of yours too much, haven't you?" Kyubi pointed towards it. "Whatever. If that's what it decides, then I shouldn't be too hasty. After all, that human boy we met was nothing more than a wimp until he took down Mckraken and saved both his world and ours." She nodded. "Twilight Sparkle has gained my interest, but not my acceptance. She will have to earn that..." With that, Kyubi vanished into smoke.

When Kyubi vanished, Venoct's scarf began to whisper to him again. Both dragons snapped and let out miniature and muffled roars. They wanted a battle.

"Calm down, Orochi." Venoct stroked his scarf once again and leapt across the rooftops, pursuing Twilight Sparkle and Whisper. "You will have your chance in the future. For now, though, I must watch over Twilight to see if she is truly worthy of facing the darkness that approaches our world."

Twilight herself felt that something was off and looked at the precise rooftop where Venoct had perched himself on. The second her gaze aimed at him, he vanished into the shadows just as Kyubi had done.

"Hey, Whisper?" Twilight gently pulled on Whisper's tail. "Do you get the feeling that something was watching us?" She looked back at the roof.

"No. Not really." Whisper himself saw the roof and merely scoffed. "If something wanted to ambush us, it would've done so by now, not just waited until we looked at it. That's the whole point of an ambush. You strike from an unsuspecting location or stance and bait your opponent into a battle that they weren't expecting.

"Still, I really do think that someone, or something was watching us..." She scratched her chin as she took one last look at the roof before she walked away with Whisper to prepare for the slumber party trap.

Author's Notes:

By the way, in case you're wondering, I've been playing a LOT of Yo-Kai Watch on 3DS, so that's where the reference to Nate comes in.

If you've seen the anime but haven't played the game, Mckraken was a Yo-kai exclusive to the game alone. He was basically Squidward with a black man voice who wanted to rule both the Human and Yo-kai World with an iron fist. Nate and Whisper banded together with all of their Yo-kai to defeat Mckraken twice and save their worlds from utter annihilation.

As for Venoct, I prefer his voice to be dark and low, unlike how he sounds when you befriend him and he uses his name. And in a similar tone, I'm using Kyubi's attitude from the game, not the anime, because Kyubi's attitude is different in each version.

I really do hope that you've enjoyed this story so far, and I hope that you continue to follow the story for any future updates. Make sure to comment down below on what you liked about this chapter in that little comments box, and make sure to share this with your friends and followers, give them a great read.

See you soon!