Darkworld is a universe where the sun is completely obscured by some unknown catastrophic event, and people live in Truman-Show-like dome cities, interconnected by vast tunnels. Food is grown in massive hydroponic farms. Money is an obsolete concept. Electricity is the only currency, and no one has a 9 to 5 job. People earn a living in a communistic system of energy production: you meet your quota for the day running on a treadmill, and you're free to fritter away the hours as you see fit for the rest of the day, spending your energy credits on food, clothing, luxuries, etc. It's an almost Utopian existence where disease, hunger, war, crime and violence have been eliminated and the highest ideal is to better the world by advancement of the humanities and sciences.
There is no dark superpower above it all, brainwashing people or anything like that. All have invested themselves into the ideals of the utopian society. In a world without money, possessions or any sort of violence, there is nothing to gain by hoarding power over people.
The catch? (there's always a catch) Sex is non-existant. All are virgins. Human beings have been bioengineered in a lab for untold generations and adopted out to parents. This has been going on for so long that everyone has forgotten there's even a such thing as sex. They are not oppressed into asexuality. They simply don't know there's a such thing as sex. There's no porn, no locker-room talk, no suggestive music or TV shows. Holding hands is considered "intimacy", and hugging and kissing and caressing is the new "fourth base". People believe that their genitals are meant for urination and that's it. Erections and wetness are considered embarrassing, as is any sort of nudity in the presence of another person. All people are beautiful due to the bioengineering, and in a perfect state of physical fitness due to the constant treadmill running, and the odd feelings of arousal are always repressed as confusing and scary.
In every Darkworld story, somebody accidentally "discovers" sex somehow. Think Blue Lagoon. Think Pleasantville. Think Adam and Eve in the Garden of Eden. Of course once they've discovered sex, they begin spreading the new joy to their closest friends and those who have done it begin "glowing" in Darkworld. Something about them seems to have come alive inside. It's not something you can physically see, but in a world where real intimacy and love has been forgotten, those who have touched another soul suddenly light up somehow.
Now naturally, those still in the dark, are resistant, even hostile to this new knowledge, and problems arise for the newborn souls. There's a kind of erotiphobia, fear and hatred of those who have "defiled themselves" with this strange new activity--a lot like homophobia and racism in our society. It's seen as barbaric in an enlightened society, especially with the blood of virginity involved. Any bloodshed is considered violence, and violence is the highest sin in Darkworld.
The characters must find resolution between the new beauty they have discovered and their resulting ostracization from society. They must overcome their self-doubts and learn to accept themselves as lights in Darkworld.