Title: Ayakashi

Summary: Tsuna is half-youkai, but that's not going to stop him from becoming Vongola Decimo. At least, not if Reborn has anything to say about it. Still, something he really wishes his student wasn't quite so weird.

Notes: Originally posted on my tumblr as just something to keep me writing when inspiration waned. I'm gathering the short chapters and posting them here for posterity.


Chapter 1: His true form

Reborn considered himself to be quite experienced in the ways of the world. He had seen a lot, he had done much. He had been turned into a perpetual two year old to serve as the living battery for a magic rock that upheld the fabric of reality.

He didn't think there was much of anything left that could truly shock him.

So when Reborn punctuated his explanation of the Vongola famiglia's history and how it related to one Sawada Tsunayoshi by putting a bullet into the wall next to his new student's skull, only to have the boy screech and suddenly grow a tail, the hitman didn't even blink.

Yes, Reborn decided, it was a tail. A fox one, and rather fluffy. It had not been there when Reborn conducted his observation of Tsuna or when Reborn first arrived at the house. But there it was now.

Under Reborn's scrutiny, Tsuna froze, a horrified, terrified expression coming over his face as his entire body began to tremble. It was the face of someone expecting their very existence to be rejected, the kind of emotional blow that was far more painful than the stoning and lynch mob likely to follow.

"Just to make clear," Reborn said calmly, "I take it you're not entirely human."

Tsuna's head jerked up and down in a strained nod, his hands reaching out to grip his fluffy tail tightly. He stroked the standing golden brown fur, a shade more orange than his hair, in an effort to calm himself.

Reborn made an acknowledging noise. "So that blood is thick in you?"

"T-thick blood?" Tsuna ventured, finally letting his gaze dart toward Reborn again. His eyes were just a little too gold for a human outside of Hyper Dying Will Mode, Reborn acknowledged now.

"Having the blood of a distant ancestor express strongly within you, despite being generations apart," Reborn clarified. "The technical term is atavism."

"Oh, senzo-gaeri," Tsuna said, understanding dawning. Reborn noted the term. His Japanese was good, of course, but this wasn't a field he had ever needed to study before. "You mean return to ancestry. Um, no. Mom's a kitsune. She's a seven-tailed fox."

Releasing his death grip on his tail, Tsuna held up seven fingers to illustrate. His tail flickered, a little nervous still, but even the small show of trust pleased Reborn.

"And your father never even noticed?" Reborn commented dryly. 'That useless idiot Iemitsu,' he thought. But suddenly Nana's lack of reaction toward an infant that claimed to be a tutor, drank coffee and could haul her son bodily up the stairs made a lot more sense.

Tsuna shrugged. "He's not around much, and Mom can't change back to her real form anyway," he explained, a surprisingly dark frown coming across his face. "That's how it works. She decided to stay with him for the rest of his life and live as a human, so she can't transform, except on full moon nights and festivals."

Reborn nodded, mentally making note of it all. Information was priceless and to be hoarded, especially in an unexpected situation like this. He would have to ask later.

Tsuna's tail swung back and forth nervously as he glanced at Reborn. "Doesn't… Doesn't it bother you?" he venture finally. "The fact that I'm a hanyou, half youkai?"

"It's not that strange," Reborn said, with a careful tone of indifference. "The mafia has always attracted people with special bloodlines. Their abilities make them very sought after by many famiglie."

"I don't have anything like that," Tsuna said, shoulders and tail drooping. "I don't have any special abilities at all."

"Good," Reborn said calmly.

That made it more likely that he would be able to use Dying Will Flames. Those Flames were something only humans had, and sometimes having another bloodline could interfere with that. Nono said he had seen Tsuna's Sky Flames, but Reborn would confirm for himself. It would be his first order of business.

"Now, where were we before that little distraction?" Reborn said, hefting up his Leon-gun. "That's right. I was telling you about your great-great-great-grandfather and the mafia famiglia he created…"

This time, Tsuna listened without protest, though his expression and the way his tail curled were clearly dubious.

Even when Reborn took over Tsuna's bed and set up traps all over the room, Tsuna just grumbled and went to get the spare futon. It seemed that Reborn's easy acceptance had earned him a degree of goodwill that couldn't be dispelled with mere bullets and explosives.

He would need to keep Tsuna's heritage in mind when selecting his Guardians. They would need to be able to give Tsuna the same unconditional support.

But if anything, it made his first pick, the potential Storm Guardian, all the more suited.

"Reborn?" Tsuna ventured finally as they settled into their beds. "Are you…?"

"I'm a human," Reborn said firmly. Or at least, his situation wasn't like Tsuna's.

"Oh, okay," Tsuna mumbled, already drifting off to sleep. "Goodnight."

Listening to his soft, even breathing, Reborn let himself frown up at the ceiling. Despite what he had said, Reborn could not recall ever actually meeting a genuine halfbreed before. Supernatural beings were becoming far too rare for that. He had heard that the two halves did not always blend evenly, making halfbreeds both powerful and fragile, if their delicate balance was upset.

Well, it wasn't anything he couldn't handle, Reborn decided, wrapping himself deeper into Tsuna's blankets. They smelled a little strange, of something that wasn't quite smoke or fur. It was warm and not entirely unpleasant.

That night, he had a strange dream.

Moonlight fell through the window, across the futon on Tsuna's floor. Curled up among the spare sheets was a tiny fox kit. It shivered, having kicked off the blanket, and tried to bury its nose deeper in its fluffy tail.

Huffing sleepily, Reborn reached out over the side of the bed to pull the covers up around the small animal. His fingers brushed over its forehead. Its fur was just as soft as it looked. Drawing his arm back, Reborn drifted back to sleep.

It wasn't until morning, when Reborn drove Tsuna out of his nest of blankets by firing a few blanks into the air, that he realized what had seemed so off about the dream.

His arm, stretching out across the gap between them; his hand so large against the fox's tiny body.

'In a dream, you can't hide your true form,' he thought, before snorting at his own whimsy.

He didn't have time for dreams anyway. He had a Vongola boss to train.


Chapter 2 Those that know

Despite what Reborn had whimsically imagined, Tsuna's tail did not pop out in Dying Will Mode.

That made sense, in a way. Dying Will Flames could only be wielded by humans, and calling on them brought Tsuna's human half closer to the surface, while pushing down his youkai blood.

In a rare show of caution, what some might call hesitation, though they would certainly be shot immediately for spewing nonsense, Reborn had let Tsuna head out to school in peace and followed surreptitiously, observing.

Watching Tsuna with the knowledge that he was only half human was… almost exactly like watching him without that insight. He was still exactly the same average, cowardly, clumsy middle school student, who tripped over his own feet, cringed away from a Chihuahua, and blushed terribly when he crossed paths with the school idol.

Tsuna was also, Reborn thought privately, rather unlucky. What had seemed like a blessing — walking to school with the Sasagawa Kyoko! — had quickly turned into a curse when the kendo captain Mochida took offense and challenged Tsuna to a duel ostensibly for wasting Kyoko's time, but really just to show off.

It had been too good an opportunity to pass up, and Tsuna had caved to Reborn's prodding with surprising ease.

"You're right. Our circle is small, so we need to stick together," Tsuna had responded mysteriously to Reborn's order to protect his famiglia.

Of course, Tsuna hadn't actually stood a chance against the regional kendo champion, but that was where the Dying Will bullet came in. Just in case, Reborn had tested it that morning before Tsuna left, forcing the boy to hold it for a few moments. When Tsuna had handed it back, the bullet had been warm and pulsing faintly — in response to Tsuna's dormant Dying Will Flames.

So that brought Reborn to where he was, looking over a gym full of middle school students, watching as Tsuna, in his boxers but without a fox tail, rendered his bullying upperclassman bald. It was almost enough to make Reborn smile, or at least smirk. The Decimo-raising plan was back on track.

As the artificially induced Dying Will Mode reached its limit and the flame on Tsuna's forehead extinguished, he returned to his normal timid personality. Instinctively sensing the change, the other students cheered and began to close in to offer their congratulations.

And that's when Reborn's plans were derailed once more.

Without any warning, Tsuna seemed to poof out of existence. All that remained, Reborn saw, scrambling for Leon's scope, was a tiny fox, falling to the gym floor where Tsuna had stood.

His student had just turned into a fox, in front of half his school.

It was not, of course, beyond Reborn's ability to handle. Worst came to worst, he had a few spare smoke grenades.

However, they proved unnecessary. Before the other students could even begin to realize what had happened, the head of the school's Disciplinary Committee, Hibari Kyoya himself, dropped down into the center of the prior battlefield like an avenging angel.

Reborn wasn't surprised, but he was probably the only one to notice Hibari perched on the support beams near the ceiling during the entire match.

"For unregistered use of school facilities, fighting on school grounds and crowding," Hibari listed off, making the last one sound like the far worst offense, "you will all be bitten to death."

Tonfas flashed out, and the students scattered, much like the herd Hibari had accused them of forming. In the confusion, no one except Reborn noticed when Kyoko kneeled down to pick up the baby fox desperately trying not to get trampled by the stampede.

Soon, the auditorium was empty, except for Kyoko and her tiny burden.

And Reborn, who watched the unlikely pair with interest.

"Wow, I didn't know you could do that, Tsuna-kun," Kyoko said cheerfully, looking down at the fox kit in her arms. "Oh, but I thought you're supposed to have a leaf on your forehead, not a little flame."

"That's for tanuki, Kyoko-chan," Tsuna protested, his voice a little squeaky, but otherwise clearly his, only now coming out of an animal's snout. "I'm a fox! …And I didn't know that would happen either."

"That's the power of your other lineage — Dying Will Mode," Reborn announced, jumping down from his own hiding place.

As he approached, Kyoko crouched down to peer at him in surprise. "This is my tutor, Reborn," Tsuna introduced them, nudging Kyoko's chin with his nose.

"A koropokkuru?" Kyoko wondered, tilting her head sideways. That was another term Reborn wasn't familiar with. It was beginning to annoy him. He would have probably been even more annoyed if he had know that she had just compared him to a race of tiny beings that lived in Hokkaido.

Tsuna laughed, wiggling out of Kyoko's hold to climb on her shoulder. "No, he's a human," he said. "He's from Italy. …And he knows."

Kyoko hummed in understanding. She didn't ask why a human baby would be a tutor. Apparently, that sort of thing just didn't register when you knew a boy could turn into a fox sometimes.

"Yes, I know," Reborn confirmed. "And I take it you do too."

"My family used to mind the shrine here. Someone else lives there now, but we still have the knowledge of the spirit world," Kyoko explained. "In Namimori, the circle of people who are involved with the ayakashi is small, so we all know each other — me and Tsuna-kun, and my brother and Yamamoto-kun, and Hibari-san too."

That explained why Hibari had chosen to interfere at that moment — to cover for Tsuna — and also Tsuna's words before, about how he and Kyoko were connected.

"I forgot how cute your other form is," Kyoko commented, scratching under the fox's chin.

"Kyoko…" Tsuna tried to protest, but the happy wagging of his tail gave him away.

"So this has happened before?" Reborn asked, keeping his tone even and calm. Tsuna and Kyoko had both acted rather unconcerned, and Reborn had taken his cue from them, hoping that this wasn't anything serious — or permanent.

Training a tiny, fluffy fox as Vongola Decimo was not impossible, but it was more of a challenge than even Reborn wanted to take on.

"Yeah, a couple times," Tsuna sighed. "It'll wear off in a bit, maybe a few hours, a day or two at most."

Since there was no point in staying at the school, the two of them headed home. The baby and the fox kit made quite the sight as they walked down the streets of Namimori, especially when the fox was suddenly replaced by a boy in only his boxers.

Tsuna promptly lost his balance and fallen off the wall he and Reborn had been walking on top of.

"That was quick," Tsuna commented, then flushed as a couple of old women passing by pointed and whispered.

It had been just under an hour. Not bad, but not good either.

That form was obviously the manifestation of Tsuna's youkai blood. Reborn easily figured out why Tsuna had transformed — the Dying Will bullet had temporarily boosted Tsuna's Flames and thus his human side, but afterwards an imbalance was created, and his youkai half came to prominence temporarily.

Which meant that Tsuna was likely to experience the same thing after every time he went into Dying Will Mode. If that was true, it would certainly put a wrench in Reborn's plans.

He would have to make sure that Dying Will Mode only ran out around people already in the know about the mafia or youkai. Civilians were willing to overlook many things, including a boy running around in his boxers, screaming, with a fire on his head. Unfortunately, Reborn suspected that seeing a boy in boxers suddenly change into a fox might be too much — it went past what could be written off as human oddness into the realm of inhumanity.

That was too bad. Reborn had been looking forward to embarrassing his student by making him run around half naked at the most inopportune times.

"This is so humiliating," Tsuna complained, fruitlessly trying to cover his bare chest with his arms. He was just lucky it was summer and pleasantly warm. "Let's hurry up and head home. Hey, Reborn, do you want a ride?"

A ride?

Reborn refused to show the surprise he felt at that question.

No one had ever just asked. They either already knew he could take care of himself and left him to his devices, or they assumed he was a helpless child and picked him up without considering his wishes. There didn't seem to be any middle ground.

But, he supposed, Tsuna understood what it felt like to end up in such an annoying body, in such an annoying size.

Huffing, Reborn made a point of kicking Tsuna in the head, which was at just the right level from his perch atop the wall. While Tsuna cringed, Reborn settled on top of his fluffy hair and tapped his foot against Tsuna's forehead.

"Forward," he ordered imperiously.

"I'm not a horse, you know," Tsuna complained, even as he obediently set off.

"Then you shouldn't have offered," Reborn said indifferently.

Not that it would have mattered. If Reborn wanted a ride, he simply climbed on, whether they liked it or not. Tsuna just made it too easy.


Chapter 3: Tales of tails

Tsuna did, indeed, turn into a fox every time he came out of Dying Will Mode.

Reborn confirmed this during Tsuna's duel with Gokudera Hayato, as well as the interesting fact that the lack of serious physical beat down Mochida received was not a fluke either. Despite his wild demeanor, Tsuna did not lapse into the usual berserker rage that most experienced after being shot with a Dying Will bullet. Case in point, he did not even once attack Gokudera directly.

It made Reborn sigh. Some might consider such a kind disposition a blessing, but it was not exactly standard for a mafia boss. Though, Reborn supposed, Nono might find it charming. And it was still less weird than turning into a tiny fox at the end of the duel.

Fortunately, Gokudera had already conceded his loss, of his own volition, and accepted Tsuna as the rightful heir. Also, he seemed less concerned about the "fox" part and more worried about the "suddenly transforming."

"Juudaime!" he yelled, scooping up the tiny furry form of his new boss. "Speak to me, Juudaime!"

"Gokudera-kun," Tsuna said, "please stop shaking me. I'm getting dizzy."

Going in the complete opposite direction, Gokudera froze completely, to the point of holding his breath. Tsuna leaped out of his arms and settled on the ground in front of him, waiting. It was hard to read expressions on the face of a fox, but the nervous twitching of his tail gave Tsuna away.

"Juudaime! This unworthy one deeply apologizes for endangering and inconveniencing you!" Gokudera exclaimed, dropping straight into a full dogeza, his forehead banging against the ground. Reborn, watching this little exchange from nearby, had to wonder where and why Gokudera had learned that pose, and the archaic, overly polite language he had switched to.

He had probably studied it on the plane over. It really said something about Gokudera's hopes — and his expectations.

"Um, that's okay," Tsuna assured him. "Just… don't do it again."

"No! If you were to be attacked in this state—!" Gokudera shuddered at the thought. It was unsettling, admittedly. Reborn would never allow it, but the image of a trampled, destroyed little body, blood matting its fur, flashed through his mind.

"It'll wear off soon," Tsuna told him. "But I guess you, um, already know about… this sort of thing." His tail swished again, and the way he cringed was all too obvious. Reborn reminded himself to start working on that. It was completely unbecoming of a Vongola boss.

Gokudera's cringe was equally obvious. "Um, yes, because I'm… Well, you see…"

He couldn't bring himself to say it. Instead, slowly, hesitantly, a thin tail with a forked tip lifted behind him.

"Oh," Tsuna said, "a nekomata."

The two boys stared each other for a while longer, but that seemed to be the extent of Tsuna's reaction.

Gokudera's tail — splitting into two about halfway down its length and covered in pale fur that darkened at the tips — twitched nervously.

"Is that… Do you… know what I am?" he asked finally, not quite able to hide the hopeful note in his voice.

"You're a nekomata, right? Well, descended from one," Tsuna said. "If a cat lives to be a hundred, its tail splits in two and it gains magic powers. That's a nekomata."

That was, indeed, a cat's tail, Reborn judged. It began to sway excitedly as Gokudera leaned in.

"I heard from Mom that we used to have a cat like that in Namimori," Tsuna continued. "She belonged to a man who came here from overseas, and when she turned a hundred and learned to transform, she went to visit the place he had lived before. I haven't met one before though."

Gokudera smiled, a surprisingly bashful and endearing expression. "I see…" he said. "Thank you for telling me. I don't really know much about my mother, even though I got this from her side, and even when I tried to find her family, I wasn't able to learn much…"

Tsuna nodded slowly, understanding what a relief it must have been for Gokudera to finally have some answers.

"I'm a little jealous," Tsuna said lightly. "You already have two tails. My mom has seven, but I only have the one!"

"It's a magnificent tail!" Gokudera insisted staunchly.

"Thanks. I like yours too," Tsuna replied shyly.

It wasn't long before Tsuna poofed back into human form, still in just his boxers. As Reborn watched the two boys beam at each other, tails wagging, he felt a sudden urge to gag exaggeratedly. It was all too disgustingly cute for words. Even the warm glow of pride at having perfectly orchestrated it didn't take the edge off.

If he shot Gokudera with a Dying Will bullet, Reborn wondered, would he turn into a kitten afterwards? It was so very tempting to try it out… especially if they didn't cut out that blushing and tail wagging soon.