No one was quite sure how it had happened. Maybe it was a disease, hidden in human genes or some new strain of super-virus. Others speculated that it was alien's that did, through advance technology. Some even thought it was magic, like a terrible curse that was brought upon humanity, or a spell gone horribly awry. All of these theories where acceptable proposition, but at the end of the day no one quite knew why every person in the would had been turned into a feminine lower half.
Five years ago, the change happened as people were sleeping, meaning the eastern hemisphere didn't transform until the day after, as well as those who slept at later times. As the people slept, something happened to their bodies. When they woke up, nothing seemed immediately strange. They could see, they could smell and hear and talk. However, it was soon revealed that everyone had changed drastically. Every person, male and female ended at their belly button, as they had become a pair of pretty female legs, a feminine butt, and had retained their respective genitalia in most cases. There was mass panic as the streets were filled with legs trying to find their upper halves and the unchanged populace tried to figure out what had happened. They changed too once they fell asleep, and the human population became entirely lower halves.
People have only just now become adjusted to their new physiology, and thankfully this has not impaired them too much. People still have all of their senses, and their eyes remained as they are now placed above people's genitalia, and people speak and breath through their genitalia now, and eat with their anuses. People's legs changed somewhat too, as their legs became much stronger and hardier, and their toes became as dexterous as their missing hands were. People are still able to drive in modified cars, go to school, go to work, compete in sports and many other normal things. There were also mutant variations of halves, with some people having hands for their feet, or growing a tongue in their pussy or anus. The world is adjusting to being butts on legs, and the character we'll follow is: