Turned out a lot of students had decided to go to gym gamma.

A big part of class 1-A was here as well as some students from class 1-B. Since the sport festival was close, everyone wanted to train the most possible and improve their fighting skills before the crucial moment. That's why the school had agreed to let gym gamma open for the first year students, although not without any supervision. Both Aizawa and Kan were here to watch if everything went right.

"Hey, you're finally here!" Kaminari smiled when he saw Izuku and Katsuki enter the gym. They had taken a shower and changed into their hero costume before coming here. They couldn't risk anyone smelling Izuku's slick.

"Sorry we took some time." Izuku timidly apologised. They may or may not have gotten slightly distracted when taking a shower together...

"No problem, man! Let's get started!" Kirishima exclaimed eagerly, his excitement showing through his behaviour.

"What do you want to do?" Todoroki questioned. Although he had accepted when they had offered him to train together, he didn't see how it could benefit him. He'd rather train alone and work on his new moves.

Katsuki was the same. He didn't mind training with Izuku since the omega could keep up with him, but he was quite sceptical about the others' abilities.

"We should do matches again each other!" Kaminari proposed with a grin. There was no better way to improve than to fight against real opponents, after all. "Then, we need someone else." Todoroki pointed out and so Izuku called his friend that was training by himself not too far away from them.

"Iida!"

"What is it?" The blue-haired alpha walked toward them at the sound of his name being called, his facial expression inquisitive as he looked at them.

"We want to do a three against three's combat. Are you in?" Kirishima asked and Iida didn't seem to hesitate a lot before agreeing. "But the teams need to be balanced if we want the fight to be fair."

"Right, the three of you are too strong." Kaminari said while referring to Izuku, Katsuki and Todoroki. Since the start of the school year, it was obvious their skills were at a whole other level compared to the rest of the class. Their quirks were incredibly powerful and their fighting moves simply out of this world.

"Who do you think is the strongest out of you?" Iida asked. They needed to know if they wanted to make equitable teams.

"Me, of fucking course." Katsuki was the first one to answer, without any surprise, but Todoroki was quick to argue. "I beg to differ." The bicolored alpha scoffed, successfully riling Katsuki up in no time and earning a deep growl in response. "Shut up. I'll kill you."

"My quirk is way more powerful than yours." Todoroki stated mater-of-factly.

"Bullshit. You don't even know how to use half of it, I'll explode you in no time." Katsuki answered. Actually, fire or not, he was confident he could defeat Todoroki. "I don't think so." Todoroki replied, the tension between the two dominant alphas dangerously enhancing.

"Stop fighting." Izuku interrupted them. "Everyone knows I'm the strongest, anyway."

"Ha? The fuck are you saying?!" Katsuki snapped his head toward Izuku at the words, a menacing growl rumbling out of his throat. But the tiny omega didn't even flinch at the sound, his emerald staring right into Katsuki's crimson orbs as he held his head high.

"I'm faster." He declared.

"But I react quicker." Katsuki retorted. His reflexes were unheard of and his fighting instincts just unmatchable. Izuku's speed had nothing on him.

"I have more strength."

"But you don't know how to control it well." Katsuki once again easily discarded Izuku's argument. However, the omega still refused to back down.

"I'm more flexible." He stated, his words unexpectedly triggering a smirk to take over Katsuki's features. "That I can't deny..." The alpha said lowly while licking his lips, images of what they had just done in the shower playing through his mind.

"Kacchan!" Izuku gasped in indignation even so he playfully laughed with Katsuki.

"I don't even know if they're fighting or flirting..." Kaminari commented at the sight. "Me neither, dude." Kirishima chuckled. At any rate, it was nice to see them being this passionate about each other.

"Are we going to start this match or not?" Iida interrupted them. He really wanted to train and was tired of waiting.

"I want to fight against Deku and Icy Hot." Katsuki suddenly declared. "I'll show you who is the strongest." He smirked as he looked at Izuku and Todoroki, something predatory in his crimson gaze.

"Let's do this. We're taking Iida with us, too." Izuku grinned. He wasn't going to turn down such a defy.

"That works with me." Todoroki agreed.

"What? But we're going to die!" Kaminari exclaimed in panic. How could they possibly win against both Izuku and Todoroki? Not to mention that Iida was really strong as well. He wasn't the class delegate for nothing, after all.

"You will if you fucking slow me down." Katsuki told Kaminari with a menacing growl. He wouldn't let anyone hold him back. "Don't worry, man. We'll win for sure!" Kirishima cheered as he bumped his fits together, hardening his body for the fight to come.

"That's what we'll see." Izuku said as he got into a fighting stance too. Green lightning started to surround him, red veins travelling his whole body, when his power suddenly disappeared.

"What is it?" Todoroki frowned.

"Oh no, not again..." Izuku was quick to panic. His emerald eyes went wide as burning warmth began to swell inside him, a small pained whine escaping his pink lips at the sensation.

"What? Now?" Katsuki immediately understood what was happening. Unless Aizawa had erased his quirk, there was only one other explanation possible as to why Izuku suddenly wasn't able to use his powers anymore.

"Y-yes..." The tiny omega whimpered and Katsuki's fears were answered. "Fuck! Seriously!"

"What? What is happening?" Kaminari asked.

"He's going into heat." Todoroki responded and the beta's yellow eyes widened in alarm at the information. "Oh shit." There was no worst place to be in heat than the middle of gym gamma, when countless students and even teachers were present around them.

"Stay calm, everybody. We need to get him out of here." Todoroki tried to calm things down, but Izuku was already too far gone. His legs suddenly gave up as the warmth burning inside him became absolutely unbearable.

Katsuki was quick to catch Izuku in his arms. "T-the teachers can't see me, please... everything but this..." He heard the omega say between small whines and gritted his teeth in answer. "I know. Don't worry, kitten." He could only reassure Izuku, even so he knew how bad things were looking.

"Come on! We need to distract them or something!" Kirishima exclaimed in panic. They needed to do something and rapidly, otherwise everyone was going to know about Izuku's second gender.

"It's too late." Todoroki stated at the same time Aizawa walked toward them.

"What is going on, here?"

Immediately, Katsuki, Kirishima, Todoroki and Kaminari protectively stood in front of Izuku. They weren't going to let their teacher see Izuku going into heat, even less when the omega was currently laying on the floor and whimpering in pain. Iida stood on the side, not knowing what to do between protecting his friend or obeying the teacher.

"Don't get fucking closer." Katsuki growled menacingly.

"Watch your tone, Bakugou. I asked a question." Aizawa scowled. He was aware it was Izuku they were trying to hide behind them. He had seen the green haired boy suddenly collapse and wanted to know what was happening.

"Nothing is going on, sir." Kaminari said, although his voice was wavering and the lie in his words clear as day.

"Let me go through." Aizawa took a step forward but Katsuki prevented him from going any further. "No." The blond alpha bared his teeth, threatening pheromones starting to ooze out of him.

"I'm afraid we can't." Todoroki stated in his usual cold voice.

Aizawa frowned, ready to use strength in order to pass through them if needed, when an enormous amount of arousing pheromones suddenly filled up the whole air around them. Aizawa's eyes grew wide at the intoxicatingly sweet scent, realisation hitting him violently.

"Midoriya is in heat." He breathed out in shock.

How could it have happened? An omega in the heroic course was unheard of. It was simply unthinkable. Surely they would have found out about it during the registration. How Izuku had possibly hidden such an important thing?

"Don't fucking approach him!" Katsuki let out a particularly loud growl when Aizawa tried to reach Izuku again. His instincts were getting overwhelmed between the need to protect his omega from Aizawa and the urge to help him with his heat. He could hear the small whimpers of pain Izuku was letting out from behind him and the sounds were physically hurting him.

"Let me take care of him." He told Aizawa, his tone and gaze incredibly serious.

Aizawa understood what Katsuki meant by taking care of Izuku. He also now understood why Katsuki was being so menacing and protective over the omega. "Are you mated?" He asked, not ready to let Izuku under Katsuki's care if it wasn't the case.

Katsuki nodded and so Aizawa sighed. He didn't really have any other choice than to accept. Izuku's arousing pheromones were becoming a big problem and people were starting to look at the omega with hunger, especially alphas. Even Kirishima and Iida were putting distance between Izuku and themselves in fear of losing control over their instincts.

Izuku couldn't stay here any minute longer.

"I want you both in the principal office as soon as his heat is over." Aizawa stated firmly. "Understood?" He looked right into Katsuki's crimson eyes as he asked, his order clear and final.

"Understood." Katsuki answered.

I hope you liked this chapter, the end of the story is getting close... but don't worry, I'll have another story for you when it'll happen ;)