Kakashi shouldn't be surprised. Naruto was blankfaced at the explanation of what chakra was — the entire foundation of all life, and critical to comprehension of, well, everything related to being a shinobi — so him not knowing there was an entire spectre of gender related to one's development was arguably more reasonable to not know. But just because he shouldn't be surprised, didn't mean he wasn't.
Not for the first time, he feels the fruits of frustration bearing in his chest at the Third. Exactly what part of Naruto's childhood isolation could be skewed into protection? What was the point, if he was going about life irrespective of the world to a negligent degree?
Naruto, nursing a swollen bump on his head from Sakura's fist a moment ago, grumbles and squints accusatorily at his two other teammates, frowning. "Why is this so important, anyway? He just said we won't know for another year!?" Naruto complains. Sakura glares at him.
"No, Naruto!" Sakura exclaims. "Most people present when they're 14. We can present anytime between 13 to 16 years old. So we could be presenting soon!" She chirps, looking eagerly back at Kakashi. "Right, sensei?" She asks, and of course, Kakashi knows she knows she's right — she was the top Kunoichi for a reason — but Kakashi can't help but fondly smile and ruffle her hair. Sakura's greatest strength was her interest in knowledge, and there was always room to encourage that passion.
"Very good, Sakura," Kakashi says, and Sakura beams. He peeks at the ever-quiet third member of their team. Sasuke's expression is carefully blank. He's avoiding eye-contact with him, eyebrow twitching — and Kakashi suddenly realizes, with no small amount of shock: he likely knows very little on the subject as well. Sex ed wasn't… an in-depth endeavor in the Academy. They were children, after all, and most parents liked to have a say in what their child learns about such things. But Sasuke was nowhere near the age where that kind of a talk would take place when his family passed. Kakashi expected the boy to learn on his own; as he seemed to with everything else, and he reckons with the unfairness of such an assumption. It wasn't Sasuke's responsibility to pick up after himself when his parents died. He shouldn't have to.
Kakashi sighs, looks up and imagines shaking some sense into the Third, and returns his attention back to the three little monsters. "I think there's no harm in having a little lesson," he says, cheerful despite the vague discomfort at having to explain what should have been common knowledge for them at this point.
Sakura sniffs, clearly annoyed. "Maa, maa Sakura-chan," Kakashi says, "It's always good to have a refresher, right?"
She seems abated by this, relaxing into her position on the soft soil. A ray of sunlight pierces through the greenery above their heads, lighting the children up in flickers of gold and yellow. They all peer inquisitively at him. Kakashi shifts his arm which is slung over a wooden crutch, gesturing his hand with as much energy as he can muster with the throbbing pain of his injuries, preparing to launch into another lengthy explanation.
"As you all know, there are two sexes one can be born with: female and male. But, there are also three secondary genders that are developed later in life, at the same time that puberty occurs. These are known as alpha, beta, and omega." Kakashi explains, gauging their reactions. Sasuke shifts in his position, his mouth set and brow still creased.
Interesting.
"What's the difference?" Naruto asks, eyes narrowed and shifting impatiently.
"I was just about to explain." Kakashi says. "Betas are the easiest to start with, and probably the most common: if you are a beta, there will be no change in your current development. As you grow, you will live life as you have been, including the changes in puberty that everyone experiences—getting taller, voice changing, and the like." He hesitates, "Alphas and omegas, however, will develop scent glands. The growth of these glands is called presentation, or presenting; as in the name, it is the moment you can be identified as an alpha or omega. Scent glands develop at the neck," he points at the junction of his neck and shoulder, "The inside of your wrists," he rolls up the sleeve of his right hand, gesturing to a subtle ridge at his pulse which he's rather sure they can't see from their position, "And in the groin area." He deigns not to elaborate, returning his arms back to the handles of his crutches.
At this, Naruto looks abundantly disturbed. "Glands?" Naruto repeats, nose wrinkled. "What does that mean? Like a lump?" He shudders, clearly disgusted.
Sakura seems perturbed as well. "Kakashi-sensei, I know that we… may develop those… er, glands, but it sounds like it's painful…" She trails off. "I tried to read about it in the library but there wasn't anything in detail about how it feels, just that it happens." She admits.
It makes sense to Kakashi: most civilians were betas, and he wouldn't be surprised if her parents were no exception. He supposes the whole thing does sound uncomfortable without personally knowing how it feels.
"That's likely because it doesn't feel like anything in particular," Kakashi says. "Other than some increased sensitivity in the area, which will taper off over time, it's perfectly painless." At their dubious expressions, Kakashi sighs. "Maa… this may help to know, but I myself am an alpha."
Naruto and Sakura perk up at that, looking closely at him as if they could suddenly see the differences in him now that they knew. Even Sasuke seems more interested now, eyeing his now-concealed wrist with increasing curiosity.
"Can we see it?" Naruto asks. Sakura hits him on the head.
"Naruto! That is private!" She scolds, but her eyes betray her: also narrowing at his gloved hands.
Kakashi sighs again, and pictures shaking the Third until he was a spinning top. "This is a little unusual, but…" Kakashi shrugs, "It should do no harm to show you." Kakashi presses his crutch on his right side into his elbow, and pushes up his sleeve, leaning forward.
Eagerly, Sakura and Naruto lean in, while Sasuke's eyes narrow at Kakashi's movements, his head tilting slightly forward.
Removing his fingerless glove with his left hand, Kakashi bares his wrist to the three children, leaning forward. Other than a gentle patch of raised skin, the area was unblemished and hardly different from the rest of his skin. You really wouldn't notice it was there unless you knew to look for it.
"I don't see anything!" Naruto huffs. Sakura gives Naruto a side-eye, but then gives Kakashi a haughty look.
Kakashi chuckles. "Well, really, you guys naturally have other glands in your body that are shaped like this. Press your fingers in the junction between you neck and your jaw, above your pulse point." Kakashi gestures to the region on himself with his pointer and middle finger, readjusting his gloves over his wrist. "These are your lymph nodes. You can only feel them from the outside, and only see them on someone else if you're really looking."
Naruto frowns, squinting, as he presses his fingers to his neck; but once he feels the bulb, he breaks into a grin and starts nodding sagely. Sakura in particular is very fascinated, going between feeling her lymph nodes to peeking at Sasuke's neck not-very-surreptiously trying to estimate if she can see his.
Sasuke lilts his head just so, and the tall collar of his shirt covers his neck from her view. He seems disproportionately annoyed at the situation; Kakashi's starting to speculate the gender topic is a sore one. Sakura blushes, retreating.
Kakashi clears his throat.
"Moreover, the importance of the scent glands isn't how they look… it's what the glands do." Kakashi explains. "Alphas and omegas have a unique sense of smell that a beta does not. Everyone smells different, but it should be immediately obvious to one if another is an alpha or omega. More impressive than that, a scent can reveal strong emotions in someone, such as anger, disgust, and desire." Kakashi says. "These qualities are useful to ninja, because they reveal intent… but only to a certain point: some highly skilled nin are capable of controlling their emotions on a deeper level, leaving no indication in their scent." Kakashi pauses.
"But if that's the boring part, what's the cool part?" Naruto excitedly bursts, eyes shining and leaning forward. "Do you get stronger if you're an alpha like you, Sensei?" He asks. Sakura casts him an irritated look.
At this, Sasuke stares at Kakashi. There's a weight to it that abruptly makes Kakashi feel like he's going to be judged very critically based on his response.
"...No, not particularly." Kakashi starts. "Alphas and omegas have different predispositions due to the nature of the gender, but it wouldn't make someone any more or less strong." Kakashi says, flickering his eyes to Sasuke. Sasuke's looking at the trees now with a carefully feigned disinterest that puzzles Kakashi.
"Predispositions?" Naruto asks. "Whaddaya mean?" He's got a twisted up look of confusion on his face, drawing Kakashi back to the conversation.
Kakashi hesitates, deciding how to approach this delicately. "Well, I'm sure as you know—" Hopefully, Kakashi adds in his mind, "—women can carry children, and men can produce children. It's not fair to say all women and men act the same, but some could argue that women are more inclined to motherly traits, like high emotional intelligence and being more gentle. Similarly, men would be inclined to fatherly traits, like being a protector or head-of-household—but let me be clear. These are generalizations only to be taken at face value. There are incredibly powerful women and men who are ninjas, just like alphas and omegas. What one's gender is says nothing of a ninja's abilities or behavior." Kakashi smiles. "In fact, the Second was an omega himself."
Naruto nods along rapidly, but it's clear he's only partially paying attention. "Yeah, yeah, but what does having children have to do with omegas and alphas?" He asks. Sakura looks aghast at this question.
And here comes the part Kakashi was avoiding, "Well, just like I said before, the same goes for alphas and omegas. All omegas can carry children, including men, and all alphas can produce children, including women."
"WHA-AAT?!" Naruto exclaims. Sakura looks at him, visibly annoyed.
"You've never heard of a pregnant man before, Naruto?" Sakura asks. "Think about it! How do you think Ino was born when she's got two dads?!"
Naruto falls silent at this, then starts rocking back and forth, shivering. "Weird… so weird…"
Sakura hits him on the head. "You're being super offensive!" She yells.
"No! I don't think it's weird that…" Naruto trails off. "So I could get pregnant?" He pales considerably. "Sasuke could?!"
Sasuke looks a bit sick at this. He levels Naruto with a withering glare. "Shut up, usuratonkachi." He hisses.
"Don't be ridiculous!" Sakura says. "Sasuke's obviously going to be an alpha, duh!" She sighs wistfully with a smile, which abruptly drops. "But I'll probably just be a beta…" She grumbles, visibly frustrated. Clearly, she'd created a vision in her mind of herself and Sasuke as an omega-alpha match. Sasuke gives her an equally annoyed look.
"Naruto," Kakashi sighs. "It's perfectly normal and natural for anyone who is an omega to go through a pregnancy if that is what they desire. So yes—if you were to present as an omega in the next few years, and sometime in the future want to start a family, you absolutely could carry the child." He shrugs. "You could also, as a male, produce the child. That is a unique aspect for both alpha women and omega men."
"But how?!" Naruto says, hands twisted in his hair, face ablaze and panicked. "I don't have the… thingy for that."
Sasuke stiffens, as if realizing the exact same thing himself.
Kakashi sighs. At the very least, it relievingly became clear that this was what disturbed Naruto, rather than some misplaced bias against who ought or ought not get pregnant. Unfortunately, this is the doubly worse part he was avoiding. Maybe he could dangle the Third off a bridge, just to see if it would rewire the clearly declining connections in his brain that lead Kakashi into this situation.
"Well…" Kakashi begins, putting on a brave face for his despicable, torturous, evil team. Perhaps this would be helpful, on the off chance that Sasuke or Naruto presented as omegas, or Sakura as an alpha. Crazier things have happened. "To start, I should explain that all alphas experience a rut twice a year, and all omegas go through heat four times a year." He already wants to die. He didn't sign up for this when he became a Jonin instructor, he was supposed to be giving them a lesson on chakra, a perfectly innocent inoffensive subject for impressionable preteens.
Kakashi swallows down his dismay. "A… rut is a period of roughly four to six days where an alpha has a strong desire to reproduce." Clinical words, clinical words. "For male alphas, this includes the formation of a knot over the duration of the rut." The copy of Icha Icha: Alpha Tactics tucked into his kunai holster burns into his thigh, like a brand of shame. "But no other biological changes. For a female alpha, the first rut involves the development of…" Maybe he can pass out again if he thinks about it hard enough. Possibly, he could leave the rest of this to Tazuna: the old man should pay his due for involving them in such a dangerous situation.
"Of what?!" Naruto exclaims.
Kakashi feels sweat run down his forehead. "Of an external sex organ for penetration, located at the top of her vulva." Clinical words, clinical words. "Which will become available to her when needed." Kakashi shuts his eyes. He doesn't know how much more creative he can get. "An omega…" he mumbles and swears under his breath, "G-Goes through heat, which causes them to feel a strong desire to be impregnated…" he steadfastly ignores the warble in his voice. "All omegas self-lubricate to, aid, the process… and male omegas develop a uterus which is connected to their, ahem, available region for the duration of their heat." It's the best he can do.
Sakura levels him with an unimpressed look. Kakashi avoids eye-contact with all of them.
"Available region?" Naruto echoes, bewildered.
"Your anal canal!" Sakura exclaims.
"Oh," Naruto squeaks.
Sasuke coughs in rapid succession, his ears red.
Kakashi sighs for the nth time, tucking his crutch into his armpit so he can press a hand to the bridge of his nose. "There's more to it, but yeah… That's the gist of it." He looks to the sky. "You can figure out the rest on your own. You're ninja. Do some recon." Turning around, Kakashi throws a hand in dismissal as he walks away.
"Now — go on, get to tree climbing. I want you two to reach the top of the tree by midnight." He turns over his shoulder, and waves Sakura to him.
"Sakura, you should go protect Tazuna at the bridge for the rest of the day… you're the only one who's mastered the technique, after all."
Sakura beams at him, smugly turning back at the boys before lacing her hands behind her back and turning to him. "Thank you Sensei!" She cheers, jogging up to him, enthusiastically waving goodbye to the two seated boys still reeling with the library of new knowledge.
꩜
"Ne, Sasuke," Naruto says, leaning in conspiratorally. "What d'you think you're going to present as?"
Sasuke glares at him. "Don't be an idiot." He scoffs. He sits up, dusting off debris from his previous attempts at the tree. He thumbs open the flap of his holster, hooks his finger through the hole of his kunai and spins it until he palms the handle dramatically.
"Haaah~?" Naruto goads, popping to his feet and rolling on his heels, approaching Sasuke eagerly. "So, you never thought of it?"
"...No," Sasuke says.
"Not even about—" Naruto asks, closing in on him, "—being an omega?" He's grinning, standing right beside him, hand cupped over his mouth in a parody of a whisper.
Sasuke jolts, glowering at Naruto mercilessly. "You didn't even know secondary genders existed until 5 minutes ago," he bites. "Why don't you spend your time usefully instead of asking me idiotic questions?" As if to punctuate this point, he starts off in a run, making it a few feet on the tree and scoring with his kunai just above his last run before he falters, flipping backwards and landing gracefully on his feet.
Naruto scoffs, grumbling under his breath before unsheathing his own kunai, refocusing on his own attempts at the tree.
3 hours later, chests heaving, they lay collapsed by the foot of their own trees, taking a break in the nonstop rush of training.
"Sasuke," Naruto pants, rubbing the sweat off his forehead, hitai-ate and zip-up long discarded.
"What." Sasuke forces between shuddering breaths of air. His bangs, wet, are stuck to his similarly bare forehead.
"What d'you think you're gonna smell like?" Naruto asks as he catches his breath, then reddens as he realizes he inadvertently admitted to thinking Sasuke would be an alpha.
"I mean- what you would smell like if you were… y'know." Naruto lamely remedies.
"How am I supposed to know? Usuratonkachi." Sasuke responds, muttering something under his breath. A beat. "What do you think I'm gonna smell like?"
"What?!" Naruto erupts, jolting where he's laying. "Why would I think about that?"
"You just asked me." Sasuke reminds him.
"I-," Naruto starts, flustered, "I meant I was thinking about what I'm gonna smell like, which is something really awesome." Sasuke is silent. At the lack of reaction, Naruto adds, "... But you'd be something gross, like spoiled milk." He lamely decides, nose wrinkled.
Sasuke extends him a long, pitying look that leaves no room to imagine how unimpressed he was at that summation. Naruto shrinks under his gaze, laughing nervously.
Sasuke slowly rises to his feet, mouth twitching. "You spend a lot of time thinking about me, huh?" He smirks. "Seems like you'd be the omega." Not waiting for a response, he turns away, legs crouched in preparation to run back up the tree.
Naruto's face flushes. "I don't spe— what the hell?!" He buries his feet into the ground, leaping forward and ignoring the stumble in his step as he gains his footing. "Even if I was an omega, I'd be the first Hokage to be one, dattebayo!"
"Kakashi just told us the Second was an omega." Sasuke replies, starting at the tree. Sasuke's much farther than him, Naruto realizes with horror, as Sasuke scores a mark above his previous. At least halfway to the top… and Naruto's still several feet behind Sasuke.
Motivation reignited, Naruto shuts his eyes, steeling himself. There's no way he's letting that asshole beat him. He concentrates on his chakra flow, recalling Sakura's advice. Focus… let just a little chakra out… balance it…
There! Just as he feels what is the right amount of energy exerted to the soles of his feet, he hears something at his left.
"Naruto?" Sasuke calls.
Naruto's eyebrow twitches. Shooting his eyes open, he glares at Sasuke, who is stalwartly avoiding eye-contact.
"Teme! I can't concentrate!" He yells.
Sasuke's eyes flicker to him before returning to the ground. "...What did Sakura tell you, earlier?" He asks, voice pitched awkwardly.
Naruto's mouth drops open. Glee fills his stomach; the bastard needs his advice? Really?
He's eager to withhold it; then, he remembers their earlier conversation about secondary genders. They have 'predispositions.' So, in the spirit of dissuading Sasuke's theory about Naruto's potential to be an omega, he channels a more alpha-like attitude. Kakashi-sensei did say they were caretaker types, right? All the more reason to help the little guy, rather than lord it over him. Naruto can act the mature alpha-type, thank you very much.
Naruto sniffs. "I'll help you out, since you're asking for help, and all…" He crows, shrugging. This breaks Sasuke's stare-down with the soil, his head spinning to scowl at Naruto. Naruto generously ignores this. "Sakura-chan said that I can't concentrate if I'm stressed out, so I should relax and focus on my chakra. That way, I can feel how much or how little chakra to center at my feet. So, I've been breathing slowly to relax before I focus… and then I try to walk up the tree when I'm ready."
Sasuke hesitates, then nods imperceptibly. "Thanks," he mutters, nose dusted with pink.
Naruto grins. "Anytime!" He chirps.
Renewed vigor, Naruto returns to his ministrations at the tree. The seeds are planted now. He just needs to keep at it; he'll show that teme he's no omega.
Fantasies of alpha power and such in mind, Naruto stays out training until the sky bleeds to black.
꩜
Naruto wakes up the next morning to a pretty girl sitting over him, face backlit by the warm morning sun, her eyes kind. Her hands lift from where they were on his shoulders, tucking a strand of hair behind her ears.
"You'll catch a cold sleeping on the ground out here," she says, head tilting.
"...Hunh?" Naruto grunts, sitting up. Naruto foggily recalls Kakashi saying the same thing last night. She moves back to give him space, still smiling pleasantly. Her mouth is pink and glossy. Naruto stares at her, confused and still groggy with sleep.
"...Who are you?" Naruto asks, yawning.
Not long after, Naruto spends the morning chatting peacefully with his new friend, Haku, as he helps her gather medicinal herbs from the forest floor. He pricks his finger on a pointy plant where one herb sits, a fennel Haku called it, and winces, putting his finger in his mouth.
"What's going on that's made you get up this early to pick these?" Naruto asks, looking skeptically at the drop of blood beading on his pointer. "I mean — y'know it's dangerous around here? And you're a girl."
"Is that so?" Haku echoes, amusement in her eyes. "Dangerous enough that you were sleeping alone…"
Naruto sputters for a moment, realizing the circle he talked himself into. "Well… that's not the point!"
"Either way," Haku laughs, "You're wrong. I'm a boy."
Naruto jolts, looking at Haku in shock. "Really?!" He exclaims. "But, you're so pretty!" He says, disbelieving.
Haku blinks. "You still haven't presented, right?"
Naruto shakes his head in the negative.
"Ah… I'm an omega," Haku says.