What about a totalitarian world where the regime divides teens into Houses and we are assigned to the very House where all those the government considers a nuisance go? From outcasts to social activists, from children of rebel parents to those who literally can't afford living in a megacity. In a society where every single thing is recorded and examined, our House acts as both a reformation center and a detention facility. 

I have no idea what the main goal of ours could be, just that we could face other Houses from time to time in a championship of sorts with the prize being money(?), freedom(?), a partner(?). Or survival, if you want a darker theme.