Probably a stupid thing to say or think about, but I hope all these Onee-chans (or "rich thots") are treating the shotas right and aren't just using them as disposable boy toys. Like they're not just gonna cruelly toss them away once they get bored of them before moving onto their next "victim." Not saying they have to become best friends or anything, or marry them once they're old enough, just be nice and gentle to them and their young emotions and fledgling and rampant hormones and inevitably corrupted sexuality. Some of them do, like Rena the delinquent, but others are more questionable and unclear, at least until Sky fleshes them out more in future sexual shenanigans.
Be "responsible" and ""ethical"" shotacons. Weird and contradictory I know, but hey, this is the world of fantasy and hentai, where anything is possible. It could be worse. The shotas could be living in a world of monster girls with violent hellhounds and voracious and sadistic succubi.