The year is 2100. Humanity has developed technology that can alter someone's gender with a simple process, however gender swapping is not always in the hands of the individual.
For those still in school their gender and genitals are determined by the school policy. This is a new development and many have to deal with adjusting.
Worst of all gender shaping is still very expensive, meaning it's very difficult to swap back once you graduate. And even if you can swap back, it'll still be a long wait for many.
Gender and genitals have become like school uniform for many. Where fancy schools control students genitals for the sake of modesty or lack of distraction. For most it's bad, but it's become a part of life that all now have to deal with.