Hello! Crazy7634, here. This is an idea that just came to me while I was on a… "Gravity Falls high" so to speak. So, after I finished my binge-watching of the entire series of Gravity Falls, I couldn't get this out of my head. If you came to this fanfiction because of my Naruto and Steven Universe crossover story "A Second Chance" or my Naruto and Digimon crossover story "Son of Two Dragons", then welcome! If not, then I recommend that you check those other two stories out. Also, if you guys see any mistakes, no matter how small, then feel free to inform me about them. Now, without further ado, I introduce to you the first chapter of… Gravity Falls: Legend of the Nine-Tailed Guardian.

Disclaimer: I do not own anything, especially Naruto and Gravity Falls.

Chapter 1 - Gravity Falls?

[Deep In A Forest]

"Grunkle Stan! Grunkle Stan! Come here, look! I got another one of the gnomes!" a little boy yelled to his great uncle as he ran down a small grassy hill, capturing the small bearded creature. The child wore a red shirt, with a black hoodie. He had a red and white cap on his head an orange pine tree at the front and small dark blue canvas sneakers. He turned to his "Grunkle" who had another one of the creatures sitting on his shoulders, holding a timer and was walking calmly to his location. A smile appeared on Stan's face.

"You managed to find and catch another one? I don't know how you can keep up with those little suckers… Though considering that you have three times more energy than twenty kids on a sugar high combined, I guess I shouldn't be surprised." He said, looking down at his great nephew who was looking up at him with a toothy grin along with the gnome in his arms. The gnome on Stanford's shoulder spoke.

"3 minutes and 2 seconds, that's a new record kid!" Jeff had a smirk on his face as he congratulated the young boy, more gnomes were emerging out of the forest and into the clearing. "Nice hide today, Schmebulock!"

"Schmebulock!"

Stan looked at the sky.

"Seems you guys have had enough fun, just in time too. It's time to go home kiddo!"

The child pouted, "Already? Can't we stay just a bit-?"

What the boy was about to say was cut short as the sound of loud howls filled the area and massive wolves jumped into the clearing the four were in. Stan cursed under his breath.

"Kid, get out of here. Run!" Stan ordered as he equipped golden knuckles, and punched one of the wolves.

"But-"

"No buts except yours getting out of here. Go, NOW!"

The young boy hesitated before sprinting into a random direction into the forest, intending to get as far away from the fight as possible. The child ducked under branches and jumped over logs and fallen branches before sliding down a slope, but had hit a stray tree root and lurched forward. He screwed his eyes shut as he rolled the rest of the way down. The feeling of something scratching the side of his cheek made his eyes open in shock, only for them to widen even more when he saw how steep the hill he was rolling down was. He briefly saw yellow blurs to his right as he hurriedly closed his eyes again, but brushed it off as his hair. The 5-year-old felt as if he had been rolling down for hours, when he finally skidded to a stop. After a few minutes, the child opened his blue eyes and slowly stood up, his clothes dirty and slightly ripped in a few places. He also had some leaves and grass in his hair as well as a few cuts and small bruises due to sticks and sharp rocks. The child was awed at the sight he had found and slowly walked forward.

In front of him was an old temple made of stone bricks, cracked and mossy with age. It looked similar to a small castle and had two giant fox statues with red eyes that seemed to glow with power as he got closer. The young boy suddenly stopped, his pupils dilated when he heard a strange voice in his mind.

"I've been waiting for you, kit."

[Unknown Location]

A figure sat straight up in his bed, sweating and heart beating rapidly. He looked at the digital clock on the table beside his bed, it read 6:39 a.m.

"Another one of those eh?" He sighed as his heart slowed to a more normal rate. His voice woke the furry creature sleeping at the end of his bed.

"Those have been occurring for a while now, haven't they?"

"Yeah, they have… The question is, after all these years, why now?" The male wondered.

The animal looked at the clock.

"Whatever the reason is, you better get back to sleep. You still have a week of school before summer vacation, not to mention that you'll have work." he said, before laying his head back down on the bed.

The teen sat quietly for a minute before breathing in deeply.

"Yeah, you're right. Though I do wonder if they told them about the trip yet…" the young man sighed and went back to sleep.

[Piedmont, California.]

It was a Friday afternoon. Schools rang their bells, signalling that the day was over for the students. The ringing bells also meant another thing. It also meant that, much to the students' joy and the adults' ire, it was the start of summer vacation. To most of the children, summer vacation would be spent playing video games, watching TV and sleeping. To a certain pair of Pines twins, though they didn't know it, it was the start of a great adventure.

[In The Pines Household.]

"Uuuurgh…" a certain male twin groaned. The boy had messy, brown hair that covered most of his forehead and had two distinct hair flaps on the back of his head, a trait shared by those of the Pines family. He was wearing a red shirt with a dark blue vest on top and light grey shorts along with white socks that each had a single red stripe and black shoes which had white on the bottom. He had a game console in his right hand while slouching into his family's couch, a girl sitting next to him busy playing with their feline pet. He looked at his parents who were on the other side of them, his father sitting on an armchair with his mother standing beside him. "What?! Why do we have to go to-…? Where do we have to go again?"

"Gravity Falls, Oregon." His mother replied.

"Yeah, there. Why weren't Mabel and I told of this sooner? We had a lot of things planned."

"Because," his father interjected, "You two's plans consist of only three things. Eating, playing games and sleeping. Dipper, your mother and I thought that it would be good for you and your sister to spend your summer vacation out of the house for once, plus you haven't seen your Grunkle Stan since he got you guys to help him make counterfeit money."

The young 13-year-old boy, the now identified as Dipper, sighed.

"I guess it can't helped, besides you guys have already bought the tickets for the bus we're going in to get there, haven't you?" He asked knowingly. His parents just had sheepish smiles on their faces and were rubbing the back of their heads. Dipper sighed again, he knew his parents enough to know that their actions meant his assumption was right. "When do we leave?"

"Tomorrow"

Dipper blinked, "So soon?"

His mother, as if she read his mind, said, "You have to leave this early because it takes quite a while to get to Gravity Falls. We also arranged this so that you can spend as much time as you can there."

After sighing again, her son turned to his twin who was happily cuddling their cat. "What about you Mabel? You haven't said anything about this situation…"

The girl in question turned to her twin, not stopping her cuddling of the struggling feline. Mabel had brown hair like her brother, except hers was long and reached her hips. Her hair curled at the ends and she also had the distinctive Pines hair flaps. She had braces on her teeth and was wearing an undershirt and a pink sweater which had a picture of a shooting star with rainbow trails knitted at the front, she was also wearing a purple skirt and black shoes with white socks.

"Though I want to stay here for summer, I also want to go somewhere outside of the house for a change. Besides, like dad said, we haven't seen Grunkle Stan in a while. Plus, didn't you say earlier that we didn't really have much of a choice in the matter anyway, Mr. Sighs-a-Lot?" she replied.

Dipper opened his mouth to retort, but the sound of a car arriving then parking made him pause. Even Mabel stopped choking their cat which had a somewhat relieved look on its face. There were only three people in their family of five that could drive, and two of those were their mother and father, both of which were right in front of them, which meant that it had to be HIM. They glanced at the clock and saw that the time was 6:08 p.m., had they have been talking to their parents for that long? Shaking their thoughts out of their heads, the two dropped the things they were holding and ran to the window beside the door leading into their home as their parents smiled at their actions. Outside, parked on the driveway was a rust-orange Ranger.

'It's about time! His jobs must've taken longer than he thought they would today…' the twins thought, as the sound of keys opening the locks in their door reached their ears. A figure walked into the house and saw his parents with half-knowing and half-amused smirks on their faces on the other side of the room, which meant… the person flinched and readied himself for a powerful force to strike him. Luckily, he managed stand his ground when he felt the weight of the two thirteen-year-olds, who promptly catapulted themselves at him when he reached their peripheral vision, collide against his body.

"Oof!" was the only sound that came out of his mouth as Dipper and Mabel both gave him bone-crushing hugs, he in return gave them both a massive, playful bear hug at the same time. The twins giggling as he lifted them up, their feet no longer touching the carpet on their floor. Once the figure put them both back down, they looked up at him with large smiles on their faces and saw their 18-year-old older brother giving them both a big goofy grin in return. This, was N Pines. His full name being Naruto "N" Maelstrom Pines. His hair was brown with bright yellow tips and had three whisker-like scars on his cheeks. Unlike his siblings, his hair was spiky instead of curly and was held in a low ponytail, but he still inherited the signature Pines hair flaps; though they weren't very visible as they were hidden under the spikes. His clothing consisted of a blue shirt, an orange short-sleeved hoodie with black trim, dark blue cargo pants, black and red shoes and had a black headband tied around his head, which he wore slanted so that it hid his eye and the area around it from view. He was also wearing a black watch around his left wrist and had a necklace made of green gems tied around his neck along with a mask that covered the bottom half of his face.

The four others in the Pines household found his insistence on wearing the face mask slightly odd, but not as much as his necklace; mostly because of its appearance. It looked like it said "W an-" with the letter "n" only having its left side, as if whatever the necklace was snapped in half. What was odder was when they had asked him about it, he would get a far-away look on his face and turn to a certain direction, always looking towards the same direction whenever they asked, and seemed to be reminiscing about something while unconsciously rubbing his right arm which had a black nine-tailed fox tattoo that covered the whole arm.

"How are my two favourite little munchkins? It's the start of summer vacation today, have they told you about staying with Grunkle Stan?" N asked, his grin still plastered on his face.

"Yep! We're a bit peeved though… I mean, we were expecting to just have a summer filled with pranks, joyrides with you, video games and watching TV. But now we have to go to Gravity Falls and visit Grunkle Stan. It's just a bit sudden, you know. Also, where's K? He's always with you, plus he's so fluffy. Even if he doesn't agree to being called that." Mabel replied with enthusiasm, happy that her older brother and his partner was home.

N, after hearing that they were a little angry about going to their Grunkle's home, gave his pouting parents an I-told-you-so smirk. His parents walked over to him and gave him $10 each.

"I told you telling them last minute would be a bad idea. Plus, after all these years, I thought you guys would've known by now to not bet against me." Naruto chuckled. His parents just kept pouting. N then turned back to his younger siblings, "K is being a lazy bum and is napping at the back of the car. I'm guessing you guys have to pack right after dinner, eh. I'll help you guys with that, just make sure you bring everything you need or want to bring alright?"

The two nodded in response.

[Time - 9:30 p.m., Twins' Room]

"…so after he paid me for mowing his lawn, me and K left to go to help unload some boxes at that warehouse that set up flyers for volunteers. When we arrived, I heard someone yell. We ran and the first thing we saw was the manager who for some reason was wearing a bunny suit stuck under a pile of boxes with a dog growling and pulling at the suit's right foot." N said while chuckling along with K, retelling the occurrences that had happened earlier in the day with the twins laughing as they folded clothes and placed them in their suitcases.

"What about that Martial Arts school, are they still trying to get you to be a student. Even though you're actually BETTER than most of the "senseis"?" Mabel asked. Naruto sighed.

"Yes, unfortunately they still are." Dipper growled slightly at that.

"Dang, if only you let us, me and Mabel would be able to beat the crud out of those guys. You did teach us how to protect ourselves after all…" Naruto raised an eyebrow as his two younger siblings threw a few shadow punches into the air before he got a mischievous smirk on his face.

"You two think you can beat them up? How can you handle them, if you can't even handle... THIS!" N yelled at the end as he pounced on his two younger siblings, tickling them without mercy as their nine-tailed fox friend just shook his head at their antics. The two couldn't do anything but laugh with tears running out of their eyes, they couldn't make him stop as he was both bigger and stronger than the two of them combined but that fact didn't stop them from trying push their brother away. After a few minutes of laughter the twins couldn't take it anymore, they banged their hands on the floor signalling their surrender. The room was silent as the twins regained their breathing and as their brother grinned at them with Kurama, the blood-red multi-tailed fox that was twice their height who was lying beside their brother. Naruto and Kurama stood up as they looked at the clock.

"Okay, we're going to sleep, you guys should get some rest as well. You've got quite an adventure ahead of you guys." The 18-year-old said to his younger siblings while glancing at the filled suitcases, Dipper could have sworn that the tone his brother used in the final sentence was hinting something. He turned to the two younger Pines and saw that they were looking down, their faces looking a bit sad, "Oi, Oi, what's with the long faces?"

Mabel looked up and replied, "Well, this is our first time going somewhere without you, Mom or Dad around… We're used to spending school breaks with you as well. So this summer vacation is going to be really weird for us without you guys around..."

N sighed and had a small smile on his face, he kneeled down, making the twins look up. He looked at them and made a deal, "Alright, tell you what. I have some business with a couple of my jobs to finish, so I'll be a bit busy for a little while. But, once I'm done with them, I promise I'll drive to Grunkle Stan's with K so that we can stay with you guys at Gravity Falls for the summer as well. How does that sound?"

The twins perked up and their sad expressions disappeared and was replaced with large smiles. "That sounds awesome!" they replied in unison.

N stood up again, to leave for his room.

"Great! Now that that's over with, get some sleep. It's late." he ruffled their heads and left the room with K in tow.

[Next Morning]

Dipper and Mabel stood outside the entrance of a bus with their bags, facing their parents, brother and fox.

"Be careful, alright you two?" their mother asked.

"We will, promise." Dipper replied.

"Don't do anything that me and Kurama WOULD do whilst we're not there alright?"

"We're not as insane as you two big bro!" Mabel grinned. Their mother raised an eyebrow before turning to her only daughter.

"Mabel, you're older brother told us that he and K are going to be joining you guys in Gravity Falls a little later. Make sure that those two and Dipper don't do anything stupid… Then again, these are your brothers we're talking about." Mrs. Pines smirked along with Mabel.

"Oi! We aren't THAT bad… are we?" the response from the two boys and a growl from K just made the two females' smirks grow.

After saying their goodbye's once more and giving the four family members each a hug, the twins boarded the bus and left for Gravity Falls.

[That Night]

Naruto sat with Kurama on his bed in the room he had for 6 years. He looked at his bedside table and pressed a hidden button located on the bottom of the very first shelf. A wall silently opened up, showing a collection of items from strange diamond-shaped knives to a suit of combat armour placed on an armour stand. But out of all the items there, the one that had his attention was black, worn-out book. It had an image of a six-fingered hand on the cover, and scrawled on the inside of the hand were the letters: "Tenivgl Snyyf naq Xlhhov". He picked it up and had a forlorn smile on his face as the two stared at the book in his hands.

"Gravity Falls, huh. Of all the places…" He chuckled and looked out of his window, towards the same direction he always looked to whenever his family asked about his necklace.

'I wonder... how much has that place changed?'