I do not own any characters of Bleach, just Yukina. I apologize in advance if this is slightly AU or OOC in any way. I've also read somewhere that 1 human year is about equivalent to 10 Shinigami years. FYI, this is following Shinigami years but I will slot in the human years in brackets for easy reference. Hopefully it won't be too confusing... :(

Chapter 1

"Kuya-chann~~!"

A teenage Kuchiki Byakuya paused mid-swing as someone crashed against his back and pale slender arms wrapped around his shoulders.

He didn't even need to look to see who it was; there was only one person who would dare call him that – Kasumioji Yukina, only daughter of the Kasumioji clan. That being said, how she behaved like a common child, uneducated in the mannerisms and breeding of a noble family was beyond him. She was unruly, stubborn and way too curious for her own good, and worst of all, utterly shameless at teasing him, which seemed to be her favourite hobby despite their difference in status.

He half turned his face towards her and shot her an irritated glare.

"Get off me. And how many times have I told you not to call me that?"

"And since when have I ever listened to you?" she countered cheekily. Nonetheless she released him from her hold and lightly landed on her feet.

He turned fully now to glance at her. Dressed in a black kimono decorated with silver and pink embroidered cherry blossoms, she simply stood there with her hands clasped behind her back in mock innocence, grinning up at him. She was slightly shorter than he although they were the same age, and didn't carry the typical Kasumioji traits of blond hair and green eyes. Instead, she took after her deceased father with silvery-white hair and crimson eyes. She and her twin brother, Makuto looked very much alike in that aspect.

The twins weren't allowed out very much, with the exception of Yukina's training since she was the next head of the family. Not only were their family members well known master forgers in the art of weapons crafting, their clan was also predominantly led by females. She was most often seen with Yoruichi, who had taken the chit under her wing. Her mother, the current head of the Kasumioji clan was adamant against her training with anyone who was beneath their rank. Given that she belonged to a high-ranking noble family that was considered just below the 4 great noble families in status, that didn't leave her with many choices. Regardless, the both of them came by the Kuchiki manor far too often for his liking.

"Quit grinning at me like an idiot, it's distracting" he snapped before redirecting his focus to his own training. As the next head of the Kuchiki clan, he had no time to waste on her.

"Oh?"

Before he could react, he found her face inches from his, their noses practically touching, her crimson eyes regarding him in the most unnerving manner. "So you find me distracting?" she teased.

"Wha… what? No, don't be ridiculous, that wasn't what I meant" he spluttered, a light pink blush working its way to his cheeks at their close proximity.

"But you just said…"

"Sh… shut up! Just leave me alone!" he said, backing away.

"Don't wanna" she simply stated, moving towards him, mirroring his footsteps back.

"I know, let's spar instead!" she suggested, grabbing onto his arm.

"For God's sake just go away!" he almost shouted, trying to shake her off. He shot her a glare that would send most adults scurrying away with their tails between their legs. It never worked on her though.

"But Kuya-chan~" she whined, being completely aware that he hated any and all forms of whining.

She didn't understand what it was about him that made her enjoy getting under his skin. Maybe it was his amusing reactions – he was hot headed, irritable and easily embarrassed by the slightest form of physical contact with the opposite sex. Or maybe it was the fact that he didn't treat her like some princess, even if she was technically one. Although she wasn't exactly welcomed by the other teenager, he was the only friend she had, or as close to what anyone like her would consider a friend. She loved it here - sparring with Byakuya, or having the occasional tea and snacks with Ginrei-jisama. The thought of going back to the Kasumioji manor was stifling. She felt like a caged animal, confined to her room and only taken out for training or to parade around to guests. She wished she was born a male like Makuto.

"That's it!" he aimed a forceful kick at her, which she expertly dodged despite her lack of concentration as she had been lost in her own thoughts.

"Why, Kuya-chan, I believe you didn't even hold back a little there. Is that any way to treat a lady?"

"Tch. What lady"

"Why you…"

Shihoin Yoruichi and Kuchiki Ginrei watched from afar as the two teenagers started trading blows. That was the way they always had been; they had known each other since they were 100 (10 years old). They'd fool around and then one of them would lose their temper, unsurprisingly and more often than not it was Byakuya and they'd start fighting, only to make up by the end of the day. Despite his outward demeanour towards Yukina, both elders knew that he cared deeply for the girl, although he would rather die than admit it. Ginrei had observed the way his grandson would sneak glances at the entrance of the manor while he practiced on days that Yukina was absent. His grandson was usually composed, calm and polite to others, even if they irritated him; only Yukina seemed to bring out his true nature and worst temper. It was all rather amusing.

"So when are you planning on telling them, Ginrei-dono?" the purple-haired woman asked with a smirk on her face.

"In time"

It was just like every other day when we would drop by to visit and train together under Ginrei-jisama's request.

"Give that back, were-cat!"

"Only if you can catch me, little Byakuya"

I watched him chase sensei around as she dangled his hair tie in front of him, baiting him on purpose. And here people wonder where I picked up the habit of teasing with him.

It caught me by surprise when his red hair tie suddenly landed on my lap. I looked up questioningly at sensei standing over me.

"Take it as your training for today… and I think you'd better start running" she simply states with a grin.

I didn't need to be told twice. I took one look at his pissed off expression as he approached us and ran for it. I made a whole round around the Kuchiki estate before passing by sensei again, who was casually sitting on the roof.

"Faster, Yukina"

"I'm trying, sensei"

"Well, you might wanna try harder. He's catching up"

Honestly, I was still exhausted from Hakuda training with sensei yesterday but I forced my body to obey. Yoruichi-sensei was considered to be the most proficient Hoho master in all of Soul Society. She wasn't known as the 'Flash Goddess' for nothing. As her pupil, I took pride in mastering it as well; there's no way I was going to let Byakuya beat me at my own game.

I caught a glimpse of the black-haired boy hot on my heels. Well, if sensei says this is my practice for today, I'm definitely gonna make full use of it. I did a single hand flip forwards and as I soared through the air, I aimed my palm back at him.

"Hado 31, Shakkaho!"

"Hado 33, Sokatsui!" he countered immediately. Damn him and his Kido skills.

They rebounded off each other, causing an explosion. Seizing the opportunity, I attacked him with a series of very high speed punches with both arms, although nowhere near as fast or powerful as sensei. As his regular sparring partner, I knew Hakuda wasn't his forte.

"Bakudo 30, Shitotsu Sansen!"

He always did favour Kido. Fine, two can play this game. Sensei has been telling me to put in extra practice on my Kido anyway, I thought to myself.

"Hado 32, Okasen!" I yelled, countering his binding spell.

"Carriage of thunder, bridge of a spinning wheel, with light, divide this into six! Bakudo 61, Rikujokoro!"

Shit. Since when did he start learning high level Bakudo techniques?

"Bakudo 30, Shitotsu Sansen!"

Our spells released simultaneously and we were both bound by the other's attack. He was pinned to a wall by the yellow triangle as I was held in place by the six beams of light around my midsection.

Sensei merely laughed at us as we fumed and glared from our immobilized state across from each other.

…

Secretly Yoruichi was pleased with her pupil, not only was Yukina mastering Hoho at an alarming rate but her Hakuda and Zanjutsu techniques were impressive too. Her Kido wasn't as good but she was improving. Byakuya's Kido mastery was even more remarkable. Even with full incantation, to be able to use Rikujokoro at such a level and at his young age… But Kido aside, Yukina was more than a match for him.

"My, you two get along so well" she said with a grin.

"No, we don't!" they both shouted simultaneously.

She watched the two prodigies continue berating and throwing insults at each other with a knowing smile.