Remember how the kingdom was introduced as a matriarchy? Well, the queen happened to be away on political business when the heroes were summoned. She wastes little time putting the king and princess in their place, while also far better respecting and supporting Naofumi. Though, before that they chance upon the other princess and expected heir who's trying to be incognito, but otherwise becomes and ally, too. The next wave also shines a giant spotlight on just how much the other heroes have been fucking around and not really understanding the gravity of the situation while some added elements are introduced into the mix, but the others unfortunately remain somewhat vexingly ignorant despite the Queen's attempts to steer them straight. We'll also see the church is your typical shady entity and goes on to try and kill the heroes themselves, but not before preventing Naofumi from upgrading his class. Also get some more backstory on Raphtalia and her prior owner/abuser, which further emphasizes the darker side of what goes on in the kingdom. Coincidentally, that leads into learning more about Fio and how queens come about. The manga goes further still, and part of me suspects will get cliffhanger'd after the third wave, but the details of that are something better left until after the 2nd hits.
And while not the intent at the time of the content's original creation, I can't help but feel how the kingdom treats Naofumi as reflective of today's America. Just swap "Shield Hero" with "Mexican" or "Muslim" Whand you'll see all those -isms our glorious cheeto pushes and the deplorables eat up as gospel. Which honestly makes the initial absurdity that much more disgusting.