I DO NOT OWN BLEACH OR RENJI (though I wouldn't mind having his fine ass over from time to time)

My many, many thanks to Ren for her elf skills!

Melting Heat

Chapter 1: Life's Not Fair

Warnings: yaoi, some angst, Beta!Renji Alpha!Byakuya So ByaRen primary focus. ((Not necessarily omegaverse, as only Alphas and Betas are used and nobody is getting pregnant))

Renji had to force one foot in front of the other as he made his unsteady way to the training grounds. He didn't want to be doing this, but he didn't really have a choice in the matter.

His heat was starting today, and it was already affecting him. He didn't feel well at all, achy all over and nauseous. He'd tried calling in this morning, knowing that his cycle was going to make this a really shitty day. He'd sent a hell butterfly to Captain Kuchiki, all but begging for the day off because he thought he might be 'getting sick.'

He hadn't mentioned his heat, embarrassed and not wanting to say that in a message. Not to his captain.

His superior's reply had been short, and sounded irritated. 'Lieutenant Abarai, unless you are on your deathbed, I expect you here on time.'

So Renji had come in, struggling to do his work. He had yet to see his captain, as Byakuya had been working at the training grounds all morning. Renji had just finished his lunch break, though he hadn't eaten due to his nausea, when he had received a summons to come to the training grounds.

So of course he was headed there, but gods, he did not wanna see his captain!

So far, he'd been able to avoid any Alphas, knowing that his scent was changing. This sucked so much! Renji did not have good experiences being around Alphas when he was in heat, and here he was, about to go face the strongest, scariest one he knew of.

He'd never been around the Kuchiki heir while being at this point of his cycle, and honestly, he was terrified out of his mind. The noble was already so strict and hateful towards him… maybe he could just get done with whatever he had to do and not make any mistakes, and get the fuck out of there without his superior noticing?

He reached the training grounds and took a deep, steadying breath. Then he sniffed again, feeling a tiny flicker of hope spring to life inside him.

The powerful smell of fresh paint permeated the air, and maybe, just maybe, it would cover the scent of his heat.

Holding tightly to his shred of hope, he made his way to the arena. He saw his captain speaking to some workers, and he kept a respectful distance until the noble's conversation was over. The workers turned away, and sharp violet-steel eyes flicked to him. He quickly stepped forward, ignoring the growing ache in his muscles. "You sent for me, Captain?"

The ravenette frowned. "Yes, twenty minutes ago. You should have already been here."

Renji barely managed not to cringe at the disapproval he could hear in the quiet, hard voice. "I apologize, sir."

The older man turned, gesturing at the arena. "Come along. We are to have a sparring match to test the new additions."

X~X~X~X~X

Byakuya saw his lieutenant tense at his words, as if he'd just suggested something horrific. "A… a sparring match, sir?"

He narrowed his eyes. "Was I not clear? The construction on the additions – the walls, targets, dividing sections and so on, is finally complete. But they need to be tested before the training grounds can be used regularly. You and I have been chosen to test them."

The redhead nodded, but looked… hesitant? "Yes, sir."

Byakuya frowned – this had been a long morning already. For some reason, he had been chosen to monitor the finishing touches of the updating construction, so he'd been dealing with the workers. And the overpowering smell of fresh paint was giving him a headache.

He moved towards the center of the main arena, and he saw Renji following him, eyes on the ground. The Rukon Dog seemed to be moving slowly, and his energy felt very subdued. "Lieutenant?"

His subordinate tensed and looked up, but didn't quite meet his eyes. "Yes, sir?"

Byakuya found himself speaking in a more gentle tone than he normally used. "You reiatsu feels different. Is something wrong?"

To his surprise, the bigger Soul Reaper just seemed to tense further. "No, sir. Nothing's wrong, I… I just don't feel too hot today. But I won't let that interfere; you said we're having a sparring session, and that is what I'll do, Captain Kuchiki."

Byakuya felt his frown deepen as he contemplated his lieutenant. Something felt really 'off', more than Renji just not feeling well. And he had the distinct feeling that the younger man was keeping something from him. But he couldn't exactly force the redhead to talk. Well, he could, but he had morals, and treating the Rukon Dog that way seemed unfair and cruel.

Finally, he sighed. "Very well, Abarai. If you think you are up to this, then we shall proceed. The tests that need to be conducted include kido, spiritual pressure, shikai and bankai, as the new construction needs to be able to withstand anything Soul Reapers can dish out."

When he got a nod to show that Renji was following, he continued, "I will be conducting the kido tests myself, and I believe Captain Zaraki is going to be set loose without his eyepatch to test how well it can handle a barrage of spiritual pressure. So you and I only really need to spar with shikai and bankai."

The crimsonette nodded obediently, "Yes, sir. I'm ready."

Byakuya unsheathed Senbonzakura, still thinking about how something seemed off… something was very wrong here. "If you like, we can warm up with our Zanpakutos sealed, and when you are ready, release shikai."

The bigger Soul Reaper nodded and drew his own weapon. Without another word, they clashed, striking and blocking. Sparks flew, and Byakuya felt concern growing in him. This wasn't right – Renji wasn't moving as quickly as usual, and was barely managing to block.

When their blades met, he could tell the younger man was shaking, and every strike, he was backing the Rukon Dog up.

Then Renji leapt out of range, desperation in his eyes and voice as he swept one hand along his blade. "Roar, Zabimaru!"

Byakuya watched as one of the most aggressive zanpakutos he knew was released.

X~X~X~X~X

Renji was trembling as he called forth his shikai. Gods, even the sort clash with their zanpakutos sealed had taken a lot outta him!

His fanged shikai blazed out, reflecting the wildness and fierce aggression in his soul.

He realized he was panting for air, and was sweating to the point he could feel his uniform sticking to his back. His captain was watching him with narrowed eyes, as if trying to figure something out.

Desperate to not let his Alpha-born superior find out that he was in heat, he swung Zabi, and the hinged blade shot out towards his opponent. The noble easily dodged, narrow chrome eyes still fixed on him. Renji could feel his strength draining away, and he tried to attack again. He missed by a freaking mile, and his eyes widened in horror as the smaller Soul Reaper held his zanpakuto up. "Scatter, Senbonzakura."

The tiny, lethal blades surged towards him. He raised Zabi to block, but his heat was fucking everything up. In all their sparring matches over the last year or so, since Aizen's defeat, he'd always managed to avoid getting cut by the older man's shikai.

But now… Renji couldn't stop the yelp of pain he made as several shimmering blades reached him. His cheek, shoulder, arm and thigh began to burn. He knew that they were only little cuts, but his stupid cycle made him hurt so much more.

The electrifying pain was so intense, he dropped to one knee, breath hissing between clenched teeth. Gods, he was so fucked if his captain attacked again.

He was barely managing to hold Zabi up with one shaking arm, a pathetic attempt to block if those blades came at him again. He cringed when he heard a metallic rush, the sound of Senbonzakura on the move.

But he wasn't struck again, and he looked to see the lethal pink blades shimmering back into the form of a sealed zanpakuto. And, oh shit, Byakuya looked pissed.

He began to tremble as his superior strode towards him. "I'm sorry, Captain. I didn't mean to screw up."

The ravenette stopped at his side, looking down at him, but Renji couldn't meet his eyes, staring down at the ground as he willed his body to stop trembling.

At that moment, the wind picked up outside, blowing through the open windows. The smell of paint began to fade, and Renji heard a relieved-sounding sigh. He glanced up to see the smaller Soul Reaper rubbing his temples, muttering, "That's better; the paint smell was giving me a headache."

Renji tensed – if the smell of paint was fading, then… Suddenly, the Kuchiki heir's eyes widened and met his, then narrowed. "Lieutenant Abarai, what is the meaning of this?"

Realizing the older man had caught the scent of his heat, Renji surged to his feet, only for his legs to buckle weakly under him, and he fell right on his ass.

Byakuya stepped forward, and Renji scrambled backwards on the ground, holding his fanged sword up defensively. His captain stared at him for several moments without moving or speaking, then a sound caught their attention.