The world is made up of three secondary genders: alpha (15%), beta (80%), and omega (5%). Though taking up a small percentage of the population, alphas tend to be volatile with little known resources to keep them calm. Other than omegas, of course. As such, alphas in high positions or law enforcement are assigned omegas who remain unmated after 22. The omegas can even be shipped from anywhere in the world if necessary. This kills three birds with one stone: alphas are regulated, omegas are housed and protected, and heirs are easily procured. Pro heroes especially need regulations, as most of them are alphas, with a few betas in the ranks. However, there are no omega pro heroes as their coworkers to help regulate them on the job, as the field is dangerous and thus isolated only to those deemed able to handle it. A field with zero omegas is one where regulation must be guaranteed at home. Thus, Katsuki just recently turned 22, the age that he will start being matched.