I had an idea at 5 am to combine my two favorite Rising of the Shield hero aus. So in this Naofumi is a girl and an omega from the abo universe. Also I'm adding Naofumi's younger brother in, and his name is Yuu. I'm really sick of seeing omega in this weak state during their heats, so Naofumi during her heat isn't like that at all. Also for a reference in this au, I imagine Fem! Naofumi to look like Byleth from Fire Emblem Three Houses but with black hair and green eyes. So lets get this party started!

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If Naofumi knew anything is that, as an omega, society would treat her differently. Omegas were rare in her world, less then 3% of the population worldwide. It made sense that the population was low. It was common knowledge that omegas were dangerous. They would break arms, rip skin off a person's face, and horribly scar a person. In the past, they were killed once they were born or used as breeders. It wasn't until the last century when the omegas were scarcily born and the overall birth rate plummeted, that the world decided to treat omegas well.

Omegas weren't the bottom of the social caste anymore. They were a ticket to the very top, and Naofumi's family knew that. Her mother and father were attempting to raise her as the perfect omega wife. She had to be home schooled with as little contact with other children as possible. They couldn't risk her mauling the face off of a ten year old. They taught her how to clean and cook. Hell, they would even make her watch the neighborhood kids, so she could get a better handle on child rearing. Naofumi didn't want to be a house omega at all. She wanted to have a job and make her own money, not to be dependant on an alpha for her entire life.

Her brother, Yuu, was born an alpha. A surprise for their beta parents with no previous alpha lineage. The standards for him in society were completely different. He was expected to become a doctor or a lawyer, maybe even a CEO. As soon as he went to kindergarten, their parents constently pushed him to be the best. He had to learn three different instruments and excel at each and every one of them. Yuu had to join soccer and one day become captain of the soccer team. He had to have the best grades, anything lower than a 90 was failing. Naofumi couldn't count the how many times his brother would come to her in tears due to stress. She would pat his head and rub his back to comfort him.

Naofumi couldn't lie. She always felt a tinge of jealousy when it came to her brother. Yuu was allowed to go outside, while she was locked inside the house because she was an omega. It wasn't his fault he was an alpha like it wasn't her fault she was born an omega. Naofumi wanted to experience the world before she had to mate with an alpha.

After begging her parents for months, they allowed her to start highschool. Naofumi used scent blockers and had her brother scent her uniform, so she wouldn't be sought after as an omega. She wanted people to like her as she was. It was all going well. She made a friend or two, the first friends in her life. She recieved pretty average grades and even joined the anime club. That year was the best year of her life, but it didn't last long.

Her friend had grown supicious on why Naofumi would be out for a week every two months. Naofumi trusted her friend and told her the truth. Naofumi was an omega. Her friend treated it like it wasn't a big deal, and that made Naofumi so happy. The next day, Naofumi being an omega was the talk of the entire school. As soon as she stepped through the gate, people walked up to her and started talking. At first she thought they could be new friends, but as she walked through the hallways everyone kept staring at her. When she got to her classroom, she saw her desk littered with scented items. Naofumi had to get a teacher to clean her desk. If she had touched any item, it would mean she accepted their gift and began courting each other.

When Naofumi approached her friend, he came clean. He told a few upperclassmen about Naofumi's omega status to get on their good side. He even offered his older brother's hand in marriage. Naofumi couldn't believe it. She trusted her friend to not tell anyone about her being an omega. Everyday from then onwards was the same thing at school. Students would approach her, try to talk to her, but they all had the same intention. They just wanted Naofumi because she was an omega. They didn't care about her, just her secondary gender.

When she graduated, that's when her parents started to push the idea of marriage. They had set up marriage interviews with promising alphas. Naofumi tried to refuse any alpha that came her way no matter what. They just wanted an omega, they didn't want her. Naofumi started to rebel. She cut her long hair into a choppy shoulder length do. She had her brother scent all her clothing that was now baggy and boyish. She started to bind her chest almost flat. She even took more scent blockers and suppressants. She could pass as an alpha when she started college.

Yuu was more than happy to help his sister. He knew how hard his parents were on the both of them because of their secondary genders. His parents refused to give Naofumi emotional support and care during her heat when she started denying any alpha thy brought to her. It was up to him to make sure his sister was cared for during her heat. That meant spending a whole week in her nest, only being allowed to leave for maybe a hour before she would cry out in distress. Yuu was the only one to help her through the week, even skipping school. His dad had slapped him a couple times for doing so, but Naofumi pratically raised him. No, she did raise him and brought him comfort when he needed it the most.

That's why he followed her to the library that day. Naofumi couldn't take her parents anymore and ran out of the house. Yuu followed her, of course. Yuu brought her to the library, he favorite place away from her parents. They both spent hours there since they were kids. So when Naofumi grabbed a book and a portal appeared, Yuu grabbed onto his sister as she was dragged down.

The next thing the siblings knew they were in another world, summonned without their consent. They were surrounded by people in robes. Three others sat by them, confused by the weapon in their hand. A spear, a sword, and a bow in the palms of the three young, alpha men. A shield was strapped to Naofumi's arm, and Yuu had nothing in his. They were apparently summoned to this world to fight the waves of calamity. Since Yuu was summoned without a weapon, he offered to learn magic instead. The king was kind enough to offer Yuu to travel to a magic academy in order to learn offensive and defensive magic. It was on an isolated mountain, north of the kingdom. He was hoping that his sister would come with him and away from the other alphas that surrounded her. Naofumi refused and urged her brother to go without her.

Yuu left the following day. He scented his sister's clothes one more time just in case an alpha got any ideas. He was on edge. He didn't trust the alphas in this world and Naofumi only had two suppressants on her. Will she be fine during her heat? She needed a lot of emotional care or else she would be in distress the whole time. What if an alpha tried to force themselves on to her? From what he learned omegas were rare in Melromarc, less than 1% were born in the last two centuries.

Yuu decided he would study his hardest to get back to his sister soon. He spent days in the academy's library, tiredlessly reviewing notes and reading grimoires. He excelled at making potions from simple forest plants. He even had a natural talent for air magic. Everyone at the academy thought that Yuu was the ideal Alpha, not that it mattered much to him. Yuu was only doing this to be useful to his sister's future adventures.

It wasn't until after the first wave since his arrival did he hear about Naofumi forcing his party member into submission and knotting her. The news was unbelievable to him. His sister was an omega! His sister couldn't have a knot. Naofumi couldn't force anyone into submission, she could break their arm but that was a different story. The whole scenario didn't make any sense to him.

Yuu had gone to the headmaster of the academy and pleaded for a carriage to carry him back to the castle. He had to find his sister and make sure she was ok. He was desperate and even kneeled down, begging to travel back. The headmaster told Yuu to forget about Naofumi. She was a disappointment to alphas everywhere. Yuu told him that his sister was an omega, that she was in danger if she had her heat unprotected. His headmaster sneered and told him to stop lying. Naofumi was worthless, a dead beat hero. The headmaster was just like his parents.

It was a few weeks later that Yuu had snuck out with a stolen grimoire and a pouch of copper coins. From what he found out, there was a villiage a days travel from where he was. There he could do some jobs and maybe get a horse to make his journey easier. He was going to find his sister no matter what.

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Hope you like the first chapter and leave a review to tell me what you think!!!