Disclaimer: I DO NOT OWN! (EITHER OF THEM!)
Who Fred and George Weasley admired the most were pranksters, especially those that managed to get away with their pranks; such as their older brothers, Bill and Charlie, who had mentioned a few pranks that they'd pulled and got away with it. The huge shocker was when their father admitted privately, about a year after they'd become successful shop-owners, that he had pulled a few "tricks" at Hogwarts before he started to date their mother.
So, naturally, when they found themselves stuck in a strange "new world", their first thoughts were not complete panic on how to get back home, but rather: how hard would it be to track down the blond kid with whiskers who was being chased for sneaking into "hanboo" headquarters where he proceeded to paint the walls orange (they weren't too sure of the name of the place).
They ended up stalking the kid for the rest of the day. He painted the monument above the town (on the faces), tied some guy's shoelaces together, put face paint on some guy who was napping, poured something that looked like juice on what looked like a guard, and performed other acts of chaos.
And he looked to be about 5.
They had found the perfect successor! Though, it would have been better if he were a red-head, then life would have been perfect.
They tracked him down to a roadside stand that was selling a noodle dish (it looked like noodles in soup). They began to plan.
Molly Weasley was the proud mother of seven children, six sons and one daughter, not counting Hermione and Harry who were her children in every way but blood (and Luna, who she'd been close to for years and become somewhat of a stand-in mother for the motherless girl, and Neville who was often dragged along to visit).
As far as she knew, in her extended family, Fleur (and her family) and Luna were the only blonds (and Neville, but it was a darker shade). Nevertheless, there was a young blond boy about the age of five sitting at the kitchen table, eating a sandwich that was identical to what the twins themselves were consuming.
"Fred, George" she greeted "are you…babysitting?"
"No mum" they chorused before Fred continued "this is our successor!"
"Oh" perhaps they had decided to adopt, but they hadn't mentioned it before "what's his name?"
The two exchanged looks of complete bafflement before looking in unison at the boy.
The boy beamed at them "ohayo! Watashi wa Uzumaki Naruto!"
The twins cowered under their mother's glare when she learned that they had joined the ranks of "lawbreakers" by performing the act of kidnapping. She did not yell at them immediately, instead she bustled about her kitchen preparing some more food for the boy who still looked hungry despite having just finished a sandwich.
After he was done, she called in Ginny to take him upstairs to try on some of the old clothes she had saved. The poor boy's clothes were very worn and obviously needed to be replaced.
She then turned to her victims…*ahem* prisoners…*ahem* misbehaving children, ignoring how the twins' trembled. She cast a ward ensuring no one outside of the room would hear her and she let them have it.
It was nice to know that even after all those years, if the twins were unable to escape her fury they still somewhat feared her "wrath".
Due to her lack of trust that the twins would return Naruto immediately, she escorted the young boy back. He was dressed in an orange Cannon's robe that had belonged to Ron that she transfigured into a jacket. She didn't change the color because he seemed to like it.
However, when she arrived in Naruto's world, she became interested in it. Perhaps a short tour wouldn't hurt…
It was a rather subdued Fred and George Weasley who walked down the stairs of the Burrow toward the kitchen. Their mother had insisted they stay over so their father could speak to them; but she had ended up arriving too late for them to receive a lecture so they had spent the night.
They were in quasi-mourning for the loss of their heir; he would have made a great student in the art of pranking.
Their mother was preparing breakfast, and greeted them absent-mindedly. They returned the salutations and took a seat.
"Hello Cousin Weasley" they chorused to the red-haired child gazing at them solemnly who was most likely a relative that their mother was watchi-…
They then froze and turned in unison.
The hair color was darker, closer to blood than fire, and he had green eyes and a distinct lack of freckles…
He was not a Weasley.
As one, they turned to silently gape open-mouthed at their mother.
Her cheeks faintly red, refusing to look at them, she sniffed "I just brought him back for breakfast" she insisted "he'll be going back home."
They beamed, knowing that their mother would most likely not yell at them again, and perhaps not even tell their father if she hadn't already.
"Well" Fred said, leaning back in his chair to eye the boy "he's got red-hair; he can be an honorary Weasley!"
"At least he looks more like one than Harry and Hermione, not to mention Luna and Neville" George offered cheerfully.
The boy shifted, tightening his grip on the stuffed toy he held.
"…watashi wa Gaara" he whispered softly.
It took a bit longer for Gaara to be taken home. For one, Ginny deemed him adorable and did her best to make him smile. She got a few, and then she insisted on healing the injury on his forehead that looked like it had been done on purpose with a knife. Gaara gaped at her when she did it.
He did like sand, however, tracking it all through the house. He had stared in amazement as one swish of Ginny's wand cleaned it up.
Since Naruto had gotten a present, they decided to give one to Gaara too.
Molly fixed his toy as Ginny grabbed a transfigured a glass ball that she deposited the sand inside and then charmed to change colors regularly. Gaara loved it, especially when she showed him that she had charmed it to be unbreakable by throwing it at the wall and dropping it on the floor a few times. Since he was five, and obviously a very young five, she charmed it so that he would always find it in his pocket if it got lost.
Unfortunately, it was then time to go back. Molly cried a bit, but once they had returned to the Burrow she rounded on the twins:
"And not one word to your father" she had hissed before going off to clean.
7 years later
Konoha—Chuunin Exams
"Gaara!" the Suna genin shot terrified looks at the newcomer, which was strange since he was obviously the youngest and the shortest of the trio.
"I'm Uzumaki Naruto!" Naruto declared proudly, adjusting the orange jacket he wore. The jacket was based off of one that he had loved to wear as a kid; unfortunately even Iruka-sensei didn't know where, or from whom, he'd gotten it and he had outgrown it eventually.
"No way!" a voice commented "it's Naruto!"
"Our Naruto"
He blinked as two identical strangers (with red-hair), pounced on him. They commented on how tall he'd gotten, that he'd obviously grown older, and for some reason they called him 'student'.
He was completely lost. Everyone else appeared to be as well.
"It's Gaara!" they then said, once more completely delighted as they 'turned on' the red-haired genin.
"He's also grown up" one commented.
"Not as tall, but he's still an honorary Weasley even though he's short."
"The hair color's still not right though."
"We could use transfiguration; and maybe draw on some freckles."
"Eyes are tricky though, we'll have to ask Hermione."
"But won't we get in trouble for kidnapping again?"
"Mum'll be delighted; and she was worried for years that Naruto and Gaara weren't getting enough to eat."
Naruto's eyes widened, remembering faintly when two red-haired people had grabbed him when he was about five on his way to Ichiraku.
Gaara was staring at them; his expression stunned before reaching into his pocket and removed a glass orb.
"Come on Fred, where's your sense of adventure? Haven't you always wanted a little brother?"
"We've already got one."
"Yeah, but Ron is a git sometimes."
"True, true."
The female Sand genin coughed delicately "I'm sorry, but, um…are you the ones who kidnapped Gaara when he was five?"
"Oh, no…"
"…that was mum."
They pointed at Naruto and finished in unison "all we did was borrow him. Mum was the one who took Gaara."
They began discussing quietly again.
"Come on, if we change the hair color we can pass them off as Weasleys."
When they began to evidently make their plan they sounded quite serious. In the end, Fred and George were not allowed to 'kidnap' Naruto and Gaara since Sakura pointed it out that both teams needed them so that they could compete in the Exams. So they decided to stay and kidnap them afterward. Naruto decided to ignore that, though a red-haired woman showed up and gave him some more of the orange clothing he remembered fondly, though insisted on hugging both him and Gaara (Temari and Kankurou had gaped in stunned amazement when Gaara had complied).
The three Weasleys handled themselves rather well during the invasion, and a few of the enemy nin who ran into the twins begged sanctuary instead of being humiliated some more.
When Gaara returned to Suna, he was given what Ginny (Fred and George's sister) called a potion to help him sleep.
The only real problem was when Tsunade attempted to punch Fred and George when they announced that they were planning on kidnapping Naruto. They dodged her punches by vanishing with a pop.
Sakura privately mentioned that she thought they were serious, since she had seen them drawing out plans on how to kidnap Naruto (and Gaara, since he was an 'honorary Weasley'). Due to the possible threat, Tsunade granted Jiraiya permission to take Naruto outside the village to train and sent warnings to Suna.
When they returned, they learned that screaming letters had been delivered to the twins before their mother arrived to drag them back home.
Since they mentioned 'hoping to return', Tsunade insisted on keeping an increased guard.
As it was, the twins did succeed in kidnapping Naruto (still a genin since he had just returned to Konoha) and Gaara (Yondaime Kazekage). They took the two to a strange house where their mother insisted on hugging them tightly and then feeding them.
When they left, the twins presented Naruto proudly with their 'merchandise' of prank items and offered him a generous sample (many of which he ended up using during battle). Gaara was given some more of the potion to help him sleep, including a little bottle that would always refill itself.
According to Temari, when Gaara arrived back at Suna he waved away the questions, went up to his room, and literally slept for three days. Naturally, everyone was terrified, or at least they were until Gaara dealt with Deidara in under ten minutes for attacking Suna during his 'nap' when Gaara wanted to get some rest (if he wasn't Kazekage he would spend most of his day sleeping).
Despite requests otherwise, the twins continued to kidnap Gaara and Naruto regularly. After a while, the search parties stopped being sent out, since the two demon carriers were always returned promptly and without harm, often carrying presents and/or food.
And when he got to be Hokage, Naruto grew to appreciate the break.
"Aunt Molly" made food almost as good as ramen.