When people would later look back at what started it all, the blame would entirely be laid on Anko's uncaring feet.
What could Anko do that already hadn't been done before to the little Jinchuriki of the Kyuubi no Yoko?
Simple.
She taught him all the hand signs for the summoning jutsu...and forgot to mention that he would need a contract with a clan in order for it to work. Learning the signs before signing a contract was extremely dangerous, idiotic, and considered suicidal at best. The reason being that an unbound summoner attempting to call forth an ally without a contract can bring out unspeakable horrors or deadly demons.
(This was also a theory behind why Gai had no fashion sense and that horrifying genjutsu which required two people to fully activate.)
So, being the lonely and curious child he was, Naruto remembered the signs and after he had a moment to himself, performed the summoning jutsu in a forested area that the ANBU rarely went into.
Luckily for Konoha and Naruto, the being he summoned wasn't interested in devouring all humanity or in complete and utter domination.
Unfortunately, she was interested in turning Konoha on it's head purely out of boredom and spite.
Naruto had summoned the soon-to-be Queen of the Changelings, and all hell was about to break loose.
Naruto stared at the odd horse thing with horn and what appeared to be bug-like wings. Said horse thing stared back.
"Who are you?" they said in unison.
"I asked first!" they said annoyed.
"HEY! STOP COPYING ME ALREADY!" they shouted.
The horse thing got annoyed to the point she whacked him on the head with her hoof...at least Naruto assumed it was a hoof...the thing had holes in it.
"Ah hem. Now, as I was saying, who are you and where did you get our contract?"
"Contract? You need a contract to summon...?" said Naruto confused.
The horse blinked.
"You mean you... Do you have any idea how dangerous it is to do an unbound summons?! You could get a tentacle demon for all you know!"
"The nice ANBU lady never mentioned contracts..."
"Whatever... I suppose if you like you can sign my contract so you don't accidentally destroy all life on this planet by mistake. My name is Chrysalis, and I am the next in line to become Changeling Queen. And you are?"
"Uzumaki Naruto! I'm going to be the next Hokage, believe it!"
"How nice. Here's the contract," she said, pulling out a scroll from who knows where.
"Uh...what do I do?"
"I forgot this is your first summoning. Open up the scroll and sign your name. Then with the hand you signed with, put your fingerprints in blood under the name. This insures that the next time you summon you will either get me, or once I become Queen, one of my minions."
"U-zu-ma-ki Na-ru-to..." he wrote, concentrating so his writing wasn't too sloppy. Then he placed a bloody handprint on the scroll under his name, and the Changeling rolled it up.
"Congratulations, you are now our first summoner. I'm going to be busy for the next few months, but after that you can summon me whenever you like."
"Okay!"
Four Months Later...
Naruto was bored, and when he was bored he did stupid things. Remembering Chrysalis' warning, he never bothered to contact her for the past few months. Though to Anko's credit, she did remember to warn him about trying to summon without a contract a week after his first attempt. Finding out he had made a new one with some sort of horse that was very intelligent did little to soothe her concerns, since he was told not to summon for a few months.
But today he had the feeling he wouldn't make Chrysalis mad if he summoned her again. So, he did, in his apartment.
Chrysalis looked amused, but not angry.
"Well, I was wondering if you would summon me again. What do you need help with?" she asked.
"Nothing really...but I was bored and I figured learning more about changelings would be more interesting than my homework," admitted Naruto.
"Such an honest boy. Alright then, what do you want to know?"
Naruto looked at her, then realized what was different.
"Is that a crown on your head?"
"Yes, it is. It means I took over the position as queen and devoured the old one. I get all the memories of the past queens and a power boost. Plus the ability to see and hear everything the drones hear."
"Cool. Sounds kinda like a bug!" said Naruto eagerly.
He was a seven-year-old boy. Of course he would find devouring and taking control of an army of minions awesome. Especially when they were as odd looking as Chrysalis.
"Yes, well Changelings do tend to have hive minds...like bees for instance. Ask away," said Chrysalis amused.
And so Naruto did. He learned everything he could about changelings since he was obviously going to be working with them quite a bit from now on. One of the things he learned was that the reason they were called Changelings was because of their ability to transform into anyone they wanted to, right down to their voice and mannerisms. Though that last bit did take a bit of time to observe.
In a bit of fun, Chrysalis observed Naruto for two full days before taking his place in an exam.
And she left the Academy seething while Naruto waited in his apartment with a minor changeling. Oddly enough he could understand them in their natural state.
"You neglected to mention that the Academy teachers...barring one...all treated you like some sort of leper."
"You get used to it," shrugged Naruto.
"It is simply unacceptable! Where are your school books?" she demanded. She liked their new summoner, and she refused to allow his natural intelligence to be ruined by these third-rate monkeys!
Naruto pointed to a small bookshelf, and her rage only grew as she read them.
"Deplorable! They have all been heavily altered and are clearly out of date! If you wait here I'll retrieve new books for you since your teachers clearly can't be bothered to," said Chrysalis.
Naruto handed over his frog wallet, which soothed her anger somewhat, and she turned into a copy of Sasuke Uchiha.
It was a simple enough plan. Even if she was discovered she would claim to be under a henge and didn't want her parents to learn she had ruined all her school books. Blaming their loss on a misused fire jutsu was the perfect cover and the Uchiha were well known for being pyromaniacs in training.
Half an hour later she returned with a new set of books, all brand new along with a few others.
Namely elemental training scrolls.
This little adventure lead to another, in which Chrysalis turned into a random genin and went grocery shopping. The shop keepers didn't think twice, believing that they were on a D rank and had split up from each other to cover more ground.
Anko's first meeting with Chrysalis was during her assigned slot in guarding Naruto. She was the first (and only) person to actually catch the transformation, and her curiosity won out. Finding that the fox kid had managed to get a summoning contract as useful as this really impressed the snake mistress. It also helped him get around the store owner's unofficial ban on anything Naruto without them knowing.
She was too amused by the charade to ruin it, though she did caution Naruto to at least warn the Hokage about it.
Sarutobi Hiruzen was just as amused seeing as he hadn't caught on to it (and probably wouldn't have, had Anko not convinced Naruto to at least fess up to the one person who could really ruin it for them) and agreed to let it continue...so long as Chrysalis didn't mind having one of her changelings as a 'transfer student' at the Academy.
Considering how bored she had become since taking over as queen, she had opted to act as a human girl herself. It would make the class uneven, but who cared about that anyway?
Iruka didn't know what to think about the transfer, only that something about the girl amused the Hokage greatly.
"Everyone, we have a new student joining us. Come in please."
A girl with straight lime green hair, green-blue eyes, and the oddest hair accessory the girls had ever seen came in. She wore mostly dark green clothing that could be mistaken for black, and shoes that were perfect for running.
"Hello everyone. My name is Chryssie Hive."
Chryssie was the nickname Naruto had given her, since he claimed Chrysalis was too long and was nearly impossible for him to spell right. He usually just called her Chrys though.
Chrys sat next to Shino, who seemed to take an interest in her. One short confrontation with the bug user later, and the Aburame heir approached Naruto the next morning in hopes for an alliance.
Apparently Shino's hive recognized what Chrysalis was (or at least knew she was a Queen Bee in a manner of speaking) and he hoped to earn a chance at her summoning contract when he realized what she was.
Befriending the village pariah was a small price to pay if it meant getting a chance at a contract like the changelings, who were so similar to bugs that it made the Aburame clan drool. Well, that and once Shino actually got to know Naruto he realized the boy wasn't that bad a friend...just a bit too loud.
And he was the only one to see Chrys' daring plan to get more books for Naruto to read. She simply acted like she stole the card from Naruto and the librarian was all too happy to give her whatever book she wanted from the shelf. Even those only available to the upper years.
Chrys acted like Naruto's bully in order to keep him ahead of the class. Though she did have to explain the situation to Hinata, who appeared to be the only girl willing to give him a chance.
Anko was sitting next to a bored Chrysalis who was in adult form.
"I don't get it. How the hell are you able to pay for all those books on an orphan's stipend?" she asked, drinking her sake.
"Simple. You know that building about a block from Naruto's apartment?"
"...Which one?" asked Anko.
"The one with the butterfly on the sign."
"The Kaen?" said Anko in shock. It was easy to forget that Naruto lived a few blocks from the red lights district. That kid knew more about the birds and the bees (and the female anatomy) than any other child his age! He was already on his way to create a perverted henge to prank people with!
"Yes, that one. Never really bothered to learn the name and the woman in charge was absolutely delighted to let me join them."
Anko stared at the odd summon.
"You work at the Kaen?"
"Mostly at night while Naruto is working on his homework. He does both of ours since they generally give him work from a year above his but they never do the same to me. He doesn't really care, because I tend to pay for ramen whenever his stipend runs out."
"Won't your people consider working at a place like that...degrading?" said Anko, thinking of how many civilian women hated those places, never mind the noble ones who were worse.
Chrysalis looked at her amused.
"My dear Anko, I rule over them. Why should they care if I chose to dance? Besides, my people don't normally wear clothes to begin with. Only certain occasions warrant wearing anything," said Chrysalis.
Which was true. She would quickly lose count of the ponies who walked around in nothing but their fur, Celestia among them.
"That reminds me... Why the hell are you out so often in our world? Don't queens normally... I don't know...rule over their people by actually being there?"
Chrysalis snorted.
"First off, changelings are more like bees than anything, particularly if the Aburame clan is correct when they assessed our capabilities. We can take the form of anything we wish, though behavior would have to be studied just so we don't get busted too quickly. Your Hokage had Naruto summon over a hundred of my minions as spies, and I make weekly reports on all the nations for him in exchange for not informing the council of my existence. My primary concern as Queen of the Changelings is to feed my subjects, and since this place has enough to live off of until I find a better option the hive could care less."
"How do you guys feed anyway?"
Chrysalis' grin did not inspire pleasant thoughts in Anko. In fact, she almost wanted to run from it.
"Want me to show you?"
Anko would later report her findings to the Hokage...though she would be exhausted during her report.
Apparently Changelings were the insect-horse equivalent of Succubus and Incubus, and while physical contact wasn't really necessary, it did make things a little easier.
Part of the reason why Chrysalis worked at Kaen. Lust wasn't too different from love after all. Plus it meant she could leave Naruto alone whenever she was really hungry.
Naruto was beyond pissed. This was his second try at the genin exam, and once again he failed because of the bushin. Chrys had gone in before him and simply summoned a few of her minions as a substitute, but he couldn't do the same without getting busted.
He didn't want anyone to know Chrys and several others were in fact summons that could change form. Hell, the Hokage had kept it from everyone because Chrys made regular reports that apparently trumped their best spymasters!
(Jiraiya hadn't been pleased when he learned that Sarutobi had a new method of gaining information that beat his. On the plus side, he now had more time to focus on his porn books.)
Fortunately the Old Man promised to put them on the same team, since Chrysalis seemed to be the only one who could keep him calm.
So, he complained to the Hokage, and after a demonstration he got a single jutsu from the big scroll that the old man guarded. Something about how the jutsu inside were a bigger pain to use on the field than dangerous.
Apparently most were quite chakra-intense, and the jounin weren't capable of handling it regularly. At least without a ton of high quality chakra pills and a long stay at the hospital after.
Chrysalis had taken only one look at Naruto's clone army before she started to teach them something he was lacking. How to direct an army of identical minions into cohesive groups. She wasn't the least bit surprised when they discovered that the clones sent back any memories once dispelled.
Apparently it was part of the reason why she had been chosen to become his summon instead of someone else.