Omegaverse is an alternate universe where both men and women can get pregnant. In this book, Alpha male and Beta male cannot get pregnant. Omegas have the highest chance for getting pregnant especially during their heat. Alphas are the top of hierarchy since they are born with exceptional abilities and body, while omegas are the lowest of hierarchy because they have heat that can cause many hindrance if not being taken properly.
Majority of people would present their subgenders at the age of 10. They will experience an unnaturally high fever as the symptom. After presenting, their built would change periodically based on their subgenders. Alphas will naturally developed a big built and have a tall height, while Betas have to work on it to have a big built. Meanwhile, omegas will naturally remain slim but will be more curvy later on, and only dominant type can work for big built but way slower than betas.
There are three subcategories for Alpha and Omega, which are dominant, normal, and recessive. Dominant alphas have strong pheromones that can make others submit to them, including normal and recessive Alphas. If an omega is exposed to this strong pheromones, they can go into an immediate heat.
On the other hand, dominant Omega has an alluring sweet pheromones that can lure recessive Alphas to their immediate rut. For normal Alphas, they won't go into an immediate rut, but their pheromones would still make their rut cycle come closer. Dominant alphas' rut cycle won't be affected by them, but their pheromones would still make the dominants go crazy. Dominant Omegas in heat will have 100% chance of getting pregnant.
Recessive Omegas are the lowest of the hierarchy. Their heat cycle is irregular (once per 8 months to 1 year, while normal and dominant omegas are once per 4 months) and their pheromones are weak. Recessive omegas also have very low chance of getting pregnant even when they are in heat.
Omegas will experience their first heat at the age of 18. During their heat, Omegas will experience high libido and high fever. To make their heat go away, they need the company of an Alpha or drink heat suppressant pills. However, as for now, those pills have bad side effects and the Omegas will suffer greatly. Consuming suppressants for a long time and never once in the company of an alpha will increase the chance of the omega becoming infertile.
Omegas also have the habit of nesting after experiencing a failure heat (when the heat does not resulting in pregnancy) or severe stress. This nesting habit is some sort of coping mechanism that make the Omegas feel safe. They will gather things that have the strongest smell of their alpha's pheromones such as clothes, bedsheets, towels, etc. and surround themselves with them in a corner. If they don't have an Alpha partner, Omegas will just hide in a place that no one can see them like inside the closet, locked bathroom, inside a blanket, etc.
Omegas in nesting period will drove away anyone, including their Alpha, as they are in a total "dazed" kind of like state. Nesting period usually lasted for 1-3 days.
Marking is an intimate activity to claim each other as their lifetime partner. A marked Alpha will not smell other Omegas pheromones beside their partner's. Alphas can mark multiple Omegas, but omegas could only be marked once. For marked Omegas, if they are experiencing heat, they can only be comforted by their Alpha partner. That's why there is now a law where Alpha can only mark one Omega in their lifetime.
Fated pair is between Alpha and Omega. As a fated pair, their pheromones matching rate is above 98%. Only a fated pair can experience rut and heat at the same time, and the sex between them is heavenly ( ͡° ͜ʖ ͡°). Because of that, the Omegas will 100% get pregnant even if they're a recessive. However, fated pair is extremely rare and there are still no record of a fated pair in South Korea.
In this book, there are no major public discrimination for omegas, but there are still people who see Omegas as just tool for sex and hindrance because of their heat.