Actually, one week was already quite optimistic.

The second day, everyone had to move to the changing rooms, boys and girls separated in two, in order to put on their hero costumes. They were going to have their first class with All Might and they couldn't be more excited.

However, as soon as Izuku started to remove his clothes, people's gazes instantly turned to him.

Since Izuku was rather small and looked absolutely adorable, nobody was expecting him to be this fit. He had amazingly defined abs, firm pecs and strong arms. His slender body was perfectly muscled but, what dragged people's attention the most were his curves...

Izuku was an omega. Even if he tried his best to, he couldn't completely hide his second gender's characteristics. His waist was slim, contrasting with his wide, beautiful hips. His ass was round and simply perfect. His whole body looked erotic and sensual.

All the alphas and even betas in the changing room couldn't help but find Izuku attractive. They felt desire and lust swell inside them at the sight of the omega in only pale, green boxers. He looked so sexy and his skin seemed so soft. They all wondered what it would feel like to touch him...

Katsuki let out a low growl as he placed himself in front of Izuku, hiding him from the eyes of the other male students.

"Kacchan? What is it?" Izuku questioned at the sound of Katsuki's growl, the omega oblivious to all the stares he was getting from the others.

"Nothing. Hurry up and get dressed, Deku." Katsuki simply answered but it was enough for Izuku to understand. "Oh. Right." The omega blushed, a dark shade of pink taking over his features. He quickly put on his hero costume and hoped nobody had caught on to why he had more curves than most. He really needed to be more careful.

They soon all finished getting changed and headed where All Might was waiting for them. The number one hero was standing tall and impressive as always, in his multicoloured costume. Nobody could possibly imagine what his true form was like...

"Today, you'll be doing one-on-one battles to evaluate your fighting skills!" He announced in his loud voice. "The rules are simple. You'll fight and the first one to force the other one out of the ring will win!" He explained.

Immediately, murmurs of excitement could be heard among the students. They couldn't wait to compare themselves to each other and see who was the strongest. Izuku was also thrilled. It would be a good exercise to analyse people's quirk and to study everyone's skills.

The first combat opposed a male alpha with hair evenly split between two colours, white and red, with a large burn scar on the left side of his face, against a female alpha with long black hair tied into a spiky ponytail.

Both of their quirks were really powerful, but Todoroki was stronger. He used a massive attack and created an enormous ice glacier that propelled Yaoyorozu out of the ring.

Izuku hummed in amazement at the sight. Todoroki seemed really strong. It looked like the alpha was a dominant one like Katsuki. It would explain his superior strength and speed.

Next combat was Katsuki against Iida.

Katsuki smirked when he heard his name, a sinister grin taking over his features. He was eager to beat the shit out of his opponent and to show everyone how weak they all were compared to him. He loved showing he was the strongest.

Iida was fast and powerful, but not enough to win against Katsuki. He was soon violently kicked out of the ring with a series of strong explosions coming from Katsuki.

Izuku cheered at Katsuki's victory. The omega hadn't expected less from the blond alpha, he knew how talented Katsuki was.

"Izuku Midoriya against Hanta Sero." All Might announced next and Izuku felt his heart jump inside his chest at the sound of his name being called. He quickly looked at his opponent, his emerald eyes landing on a tall, lean alpha with chin-length black hair, his elbows having the shape of cylindrical tape dispensers...

Surely related to his quirk, Izuku thought while he walked to place himself inside the ring. He took a deep breath as he faced Sero, the omega trying to calm his racing heart. He needed to relax and focus on winning.

"Start!" All Might shouted and Izuku suddenly jumped into action.

The combat was over as soon as it started. Things went so fast nobody had time to see what happened. The only thing they were able to see was a bright green lightning before Sero was suddenly ejected out of the ring, one swift and powerful kick from Izuku being all it took for defeating the black haired alpha.

Everyone was left speechless at the sight.

"Did you see that?" Someone breathed out, their voice full of shock.

"That was amazing." Another one said and hums of agreement could be heard among the students at the comment.

"I would have never thought he would be this strong with how cute he looks!" Someone else exclaimed.

Katsuki smirked as he listened to what was being said. During all summer, when Izuku wasn't training with All Might, he was training with him. The omega hadn't stopped working on controlling his quirk better even once. He had kept on practising and improving. He could now use about 15% of one for all without breaking all of his bones, it was a huge progress.

"Are you okay?" Izuku gasped when he realised how brutally he had propelled Sero out of the circle. "I'm sorry, I put more strength than I intended to!" He immediately apologised as he promptly joined Sero's side, offering his hand to help the alpha up.

Sero gladly took it and let out a small grunt as he stood up. He would definitely be sore tomorrow. "I'm okay, don't worry." He reassured Izuku. "But, damn, you're really strong." He complimented with a light chuckle.

Izuku blushed at the praise, his cheeks turning an adorable shade of pink. "Thank you." He timidly murmured. He still wasn't used to being complimented.

Sero couldn't help but find Izuku's reaction cute. "You're welcome." The alpha replied with a grin. He didn't mind losing against Izuku this much, after all...

"Good job, Deku." Katsuki told Izuku once the omega came back where everyone was looking at the fights. His words caused a bright smile to take over Izuku's features, the omega's beautiful emerald eyes sparkling with happiness. "Thanks, Kacchan!" He eagerly replied. Hearing Katsuki's praise meant so much to Izuku.

The next combat opposed a petite, fair-skinned girl with dark purple hair and plug-like earphone jacks hanging from her earlobes, against another short girl with a rather frog-like appearance. Both seemed to be betas and had rather similar strength.

Izuku attentively watched their combat, taking notes on everything he noticed about their quirk and skills, when he suddenly started to feel hot...

His emerald eyes immediately widened in fear at the sensation.

His heart instantly began to beat faster as his whole body kept heating up more and more, panic quickly starting to take over him. Intense warmth swelled inside him, the burning sensation all too familiar to the omega...

It couldn't be happening.

Not right from the second day.

Not here, in the middle of all his classmates.

Izuku stated to breath faster, his heart dangerously racing inside his chest. "Kacchan..." He quietly called as he grabbed Katsuki's sleeve, his voice sounding weak and shaking.

"What?" Katsuki asked. He turned his head to look at Izuku, his crimson eyes widening as he took in sight the omega's appearance. Izuku's face was completely flushed and sweat was glistening on his forehead. His respiration was coming out in short, harsh breaths...

Katsuki had already seen Izuku in this state enough time to know what was happening.

"Fuck. Don't tell me you're going into heat right now, Deku." The alpha cursed under his breath. It really wasn't a good time for this to happen. They were surrounded by all of their classmates, a big part of them being alphas...

"Do you smell this?" Kirishima asked, the question causing Izuku's heart to jump inside his chest.

"No, what is it?" Kaminari inquired. Since he was a beta, he had a weaker sense of smell than alphas. "There is a sweet scent in the air." Kirishima answered.

"You're right. I smell it, too." Sero replied. "It smells delicious. Almost like an omega's scent" He described as he took a deep breath in the air.

Izuku's whole body tensed up. He was wearing scent blockers but theses weren't enough to stop his scent when he was going into heat. Arousing pheromones were starting to ooze out of him, the irresistible scent enhancing more and more as his heat got nearer. Soon, everyone would be able to smell it and know from who it was coming from...

"Fuck." Katsuki cursed.

It looked bad, really bad. Izuku would soon be completely in heat and he couldn't let it happen. The omega already looked like he wasn't thinking straight anymore. Katsuki needed to do something and quickly.

"Oi, All Might!" He loudly called.

All Might heard it and turned around to look at Katsuki. "Yes, young Bakugou?" He inquired.

"Deku doesn't feel good, I'm taking him to the infirmary." Katsuki stated. He hadn't been able to come up with anything better but it should be enough.

"Really? Did young Midoriya hurt himself?" All Might asked with concern.

"No. He just used too damn much energy all of a sudden." Katsuki answered. The lie wasn't perfect, but it had at least the merit to be credible. Izuku used to pass out all the time from exhaustion when he had been learning to control his quirk at the beginning.

However, it didn't seem to convince everyone.

Todoroki frowned, the bicolored alpha wondering why Izuku would suddenly need to go to the infirmary when he had looked perfectly fine only seconds ago. Moreover, why did the sweet scent that Todoroki could smell in the air seemed to be coming from him...

"Do you want someone to help you bring him to the infirmary?" All Might asked.

Katsuki shook his head no. He suddenly lifted Izuku up and threw him on his shoulder, his strong arm firmly holding the omega in place.

"No, I fucking got it." Katsuki said as he began to walk away.

That was the second chapter, I hope you enjoyed it!