I very often stumble with Fem!Tsuna / Fem!27 while browsing KHR fics. They are often for All!27-but-without-the-gay purposes, and when they aren't, it's still only Tsuna who's gotten a sex change. I thought that I'd like to see some fics where this gender-bending rule applied to all the cast and not only Tsuna and only for shipping purposes, so this came out.

IF I can think up some good following scenes for this, I'll post more in the future. Otherwise, consider this a one-shot drabble.

This has been circling my mind since I drew this, by the way:

htt p:/ /xoverlover. deviantart. com/art /KHR-Rule -63-278246271

[Take out the spaces]

Horizontal Axis

He never thought he'd have to go through this again, and yet there he was, closing his eyes tightly not to lose his lunch to the bright lights surrounding his weightless body. Then, as fast as it came, the feeling was gone, and gravity had him sitting down somewhere that felt intimately familiar.

Tsuna squinted his eyes open and held his breath against the purple fumes he could see were still surrounding him, trying to calm his racing heart.

The last time he'd been hit by the Ten-Year-Bazooka, he'd woken up in a coffin. He hadn't been shot again since they defeated Byakuran and returned to their time, but he still had all the right to be wary. At least, he told himself, he was sitting on a carpet, and not stuck inside the velvety-soft insides of his (pretended) final bed rest.

"T-tenth?" came a cautious call from beyond the thinning smoke. A small prickling in the back of his head told Tsuna that he ought to recognize the voice, but he couldn't connect the soft pitch to anyone he knew...

The final wisps of lilac smoke drifted away, and the brunette was left blinking at the recognizable, well-lit room he was currently sitting in. The tree he looked at every morning after waking up was just outside the window across him, and there was a familiar pair of brand new sneakers sitting on what was definitely his desk. If he looked to his right, he could see his messy bed, with piles of clothes he'd been supposed to put away before Gokudera and Yamamoto came over but hadn't gotten around to doing.

Everything seemed... normal. Like the past. Or, well, the present. Had the Bazooka malfunctioned? Maybe it had sent him ten minutes into the future instead of ten years?

"That was scary," he breathed shakily, running a hand through his messy brown hair.

"T-ten-!"

"Haha, wow, who are you?"

Having forgotten all about the voice he'd heard a moment ago, Tsuna's head snapped quickly towards the unknown voices coming not three feet to his left.

He was met with a recognizable grin, and wide green eyes staring right at him. He knew the features like the back of his palm, but there was something weird about them, something softer. And without meaning to, Tsuna's eyes wandered down. His heart almost stopped when he spotted the soft curves of breasts pressing out from behind Namimori's uniform shirts, which were absolutely not supposed to be there.

"HIIIIIIIIEEEEEEEEEE!"

"Tenth!" Gokudera – or the girl who looked like Gokudera – cried at once, leaning over the low table in the middle of the room when Tsuna fell back in shock.

"Is it really Tsuna?" Yamamoto's look-alike asked, also leaning over to get a better look, and Tsuna performed a pretty neat imitation of a crab in his attempt to scurry to the far wall.

"Of course it is, you idiot!" Girl-Gokudera snapped, glaring at her cheerful friend in a way that made Tsuna feel slightly more at ease. But then her eyes were back on Tsuna, and he froze again, even when he saw the familiar look of guilt his Storm Guardian usually got when he thought he'd disappointed him. "T-the Tenth is a man in the future..." The girl bowed low, slamming her head against the floor of Tsuna's room every few words, "I had no idea the Tenth wanted a sex change! I am a horrible right-hand woman! Tenth, please forgive me!"

What? Tsuna's mouth hung open for a second, trying to decipher what Gokudera's look-alike had meant with that, but Yamamoto's female clone spoke first.

"What are you talking about, Gokudera? Tsuna doesn't look any older than yesterday."

Her forehead was an angry red when she looked up, but this time Gokudera looked at him much more carefully. Despite the similarities between this person and his Storm Guardian, Tsuna couldn't help it when his face heated up again. This was probably the first time a pretty girl checked him out, and he wasn't even sure if it counted. He also wasn't very sure how he felt when about thinking a girl-Gokudera was pretty.

"But that was the Tenth-Year-Bazooka, wasn't it?" There was a scowl in her face now, and Tsuna felt a bit freaked out that it was as scary in her face as in his Gokudera's.

"I-I thought it was," Tsuna offered meekly, finding his voice at last. "It, it's you, isn't it? Gokudera-kun? Yamamoto?"

Yamamoto's easy grin seemed enough of a reply, and from the way her eyes were glinting, she was as interested in Tsuna's form as Gokudera.

"So how come you're a boy now, Tsuna?"

"Eh? I-I was going to ask why you two were girls!" he blurted out before he could help himself.

Gokudera and Yamamoto exchanged perplexed looks before facing him again, both wearing confused expressions.

"We've always been female," the silverette said slowly, not patronizingly, rather as if she was trying to figure something out. Thin eyebrows furrowed in thought. "What is the last thing you remember before the smoke, Tenth?"

What? Well, his room had been in a bit of disarray, but he could clearly remember Lambo and Gokudera's loud yells, and the way the large bazooka had all but toppled on the low table and onto Tsuna, firing itself. It had been too sudden for him to move out of the way of the pink bazooka... Wait. Wasn't Lambo's bazooka purple? And if he focused hard, Tsuna thought he could remember a familiar symbol on the side of the weapon that had flown towards him. A crest with a bullet and a winged clam...

Light brown eyes flew wide in realization. "Giannini!"

"That dumb mechanic!" Gokudera growled, her fist clenching in anger at the thought of him.

"Haha, what did she do this time?" Yamamoto mused aloud, crossing her arms on the low table between them and resting her chin atop them. Her hair was longer than Yamamoto's but just as wild, curving along her neck and sticking out in all directions.

"I'm not sure. He's been staying with us while he experiments with some new weapons. Lambo must have taken some of them."

The mechanic had asked for Lambo's Bazooka at one point, and remembering what had happened last time the mechanic tried to fix their weapons, Tsuna had vehemently refused to let him touch it. The man had looked crestfallen, and had pleaded his case while talking about making something 'like the bazooka' that could travel on the horizontal axis rather than the vertical one or something like that, but Tsuna had stood his ground for once.

Unsurprisingly, the refusal had done little to deter the short man, who had been going on and on about his experiments since they returned to the future and told him about what had happened. Byakuran, the Vongola box weapons (now turned rings), and how they marked the difference among all the different parallel universes in which their enemy had already succeeded.

Hold on. That was it!

If the vertical time axis had pulled them ten years into the future to fight Byakuran, then the horizontal axis meant...

"This is a parallel universe."

He had completely missed the point at which Gokudera and Yamamoto had begun arguing (rather, the point at which Gokudera lost her patience and began yelling at their black-haired friend), but both turned their attention to him when he spoke.

"A parallel universe?" Tsuna could almost see the gears turning in Gokudera's head, and the exact moment when she understood. "Of course! And you must've come from a world where the three of us were born the opposite gender. That's why Tenth is a boy and seems surprised we're girls."

He felt as though his soul was going to just up and leave him. How did he manage to end up in these crazy situations?

"How can you be sure it's only the three of us?" Yamamoto asked, although it was hard to tell if she really knew what they were talking about. Tsuna's Yamamoto would continue treating the mafia as a game back home, but from time to time you'd catch a sharp glint, or a dangerous narrowing of his eyes, and then you knew he understood more than he let on.

"It's obvious, isn't it? Tenth, please tell us which members of your family are female!"

"W-which?" Tsuna gripped his hair with both hands, and was shot sympathetic looks by the other two occupants in the room. "U-um, well, Chrome is, and Bianchi, and Lal Mirch..."

Come to think of it, he didn't know if he could count the later two as part of his family. Bianchi allied with them because Reborn did, and Lal Mirch worked with the CEDEF.

"Chrome? As in Dokuro Chrome? Mukuro's friend?"

"That wench is incapable of having friends," Gokudera snapped, though without his-her usual bite. It looked like she'd swallowed a nasty bug as she continued, "I know who Lal Mirch is, but... Could this Bianchi person be my alternate self's sibling?"

"Y-yes, Poison Scorpion Bianchi."

"Dokuro Chrome, Lal Mirch, and Poison Scorpion Blanco are all male," Gokudera declared. "Everyone else with close ties with the Tenth are female."

"E-everyone...!" A fleeting thought went through his mind faster than he could stop it. "E-even Reborn?"

"Especially Reborn!" Yamamoto replied with a big grin.

"HIIIEEEEE!"

It was too much for his poor mind to take, so Tsuna just flopped backwards and passed out.

Sawada Tsuna was not a normal person. Just one look at her full name, Tsunayoshi, would begin hinting at that.

Normal girls were not given such uncute names, but Tsuna had had a very strange ancestor, a woman who had not cared that "Sawada Ieyasu" was most definitely not a female name when she moved into Japan from Italy. The rest of her ancestors must not have been any better, because they continued what was now the tradition of naming girls after Tokugawa Shoguns.

Tsuna could accept a small weird thing like that. She liked her name. What she didn't like was being a candidate to become a Mafia Boss, which, by the way, was also her ancestor's fault.

And while becoming a candidate for the title of Vongola Tenth had brought her many joys in the form of friends, it still meant Tsuna had to face many strange situations on a daily basis. Today's events were a prime example of it.

"Would you like some more tea, Tenth?"

She fidgeted in her seat, feeling beads of sweat form on her temples.

"Ah, no, thank you Gokudera-chan."

She thought she saw a pleased blush spread across the familiar peachy skin of the silverette across her. This was normal enough, except that pleased blush usually rested on a girl's face. Tsuna looked at Gokudera's lean chest, masculine shoulders, and the sharper curve of the jaw.

This Gokudera was definitely not a girl.

"Haha, you're making Tsuna all uncomfortable," and while her Yamamoto's arm was toned thanks to baseball practice, it was not as thick as this one.

Tsuna felt her cheeks heat up at the close contact with Yamamoto's male clone, although being honest, it was just what her Yamamoto would do, too.

"You idiot, take your arm off her! Stop being so familiar with the Tenth, specially when she's a girl!"

"It's fine, Gokudera-cha— ah, no, I mean, Gokudera-kun—"

"Y-you can call me Gokudera-chan if you want to, Tenth!"

His eyes sparkled with adoration, and it was just slightly creepy to see this level of devotion coming from a boy. And if she'd understood half of what Gokudera had said ten minutes ago, there was a male version of herself facing a similar situation right now. She idly wondered if he was doing any better than she was.

A sniff pulled her attention away from Gokudera and Yamamoto, and he looked over to where a child in a cow-printed pajama was holding her – no, his, head with both hands. The child was glaring in their direction with wide watery eyes, but at least he wasn't sizzling, unlike the stout man tinkering away next to him.

"Idiot Stupidera," Lambo sniffed, only to shriek and hide behind the mechanic when the bomber pulled out a set of dynamites and glared darkly at him. Green eyes latched on to Tsuna, but the girl did her best to pretend she didn't notice, instead nursing her cup of tea.

She liked Lambo, but it was his fault Tsuna was here in the first place. Well, maybe not completely his fault.

"Err, so, Giannini, how am I going to get back to my world?"

"I'm not sure yet," the mechanic said, quickly waving his arms around when Gokudera's glare was directed to him instead. "T-the X Axis Bazooka is only a prototype! It wasn't ready to be used yet, I had no idea it was actually going to work! I'll need to run a few tests, and use the Ten Year Bazooka to make a few comparisons, but it could take days to pinpoint how to reverse it."

"D-d-days?" Tsuna asked, wide-eyed.

"There's always the possibility it will wear off on its own," Giannini was quick to say, no doubt trying to be reassuring. It didn't help the situation at all.

"Couldn't we call Shoichi and Spanner? Those guys definitely would be able to help."

"They're our age right now, they won't be very useful."

"It's fine! They got their memories from the future too, didn't they? The kid said so."

"Che. I hate those guys, but if it helps Tenth return safely to her universe..."

Tsuna felt lost now. She'd been out of her depth from the moment she was sent to this alternate world where every girl she knew was a guy, but she'd been able to follow most of what had been said. Until now.

"Who are those guys?" she asked curiously.

"Who?" Yamamoto asked, from where he'd moved to fetch Gokudera's schoolbag.

"Shoichi and Spanner."

Three sets of eyes locked in on her, with varying degrees of confusion. Gokudera had stopped halfway through the motion of lighting up a cigarette, and spoke around it with a considering look.

"You don't know who they are, Tenth?"

"Um, no." Should she? It must be something mafia-related, if they were going to help with Giannini's experiments. Gokudera frowned, and Tsuna watched as the bomber and the baseball player shared a gloomy look.

"One of the universes where Byakuran took over," the silverette murmured, his lips pressed to a grim line.

"So in the future, this Tsuna..."

There was an uncomfortable, heavy silence that sent shivers up Tsuna's spine. The girl shifted under the weight of her friends' gazes, her intuition ticking something fierce. She didn't think she wanted to know what had made those dark lines appear in their faces. But as quick as the dark mood came, it was gone, replaced with a shake of Gokudera's head and a glint of pride to his eyes.

"No. Tenth defeated that guy. This Tenth's universe – all the universes, they're safe from his reach."

Yamamoto's bright smile was back, and after a bit of rummaging in the school bag, he tossed Gokudera's cell phone over the table. Tsuna was all too glad to see the darkness lift from the baseball player's face. She didn't think she'd seen such a scary expression on her own Yamamoto Tatsuya, not even at the end of the Ring Battle, and she had to return a smile when the grin was turned towards her.

"Oi, Tsuna, while those guys are fixing the bazooka, do you want to go out to the movies with me?"

Gokudera shrieked into his cell phone (possibly busting the eardrum of whoever had picked up) before Tsuna could even register the request.

"Y-YOU BASEBALL FREAK, YOU CAN'T JUST ASK THE TENTH ON A DATE LIKE THAT!"

"Haha, what are you talking about?"

"Don't play dumb, baseball idiot!"

It wasn't the kind of crazy she was used to, but it was close enough that Tsuna knew she'd feel at home for as long as she had to stay here.