So, any predictions about the humans' society (on the humans side)?
The promise was made centuries ago, and some humans were left as gifts. This is the information Sung-Joo relayed to us, and for now we should assume this to be true. However, this doesn't mean it's common knowledge on the human side. History is what is written, and really I could see it going a few ways. Here's a few scenario's that could come to be...
- The human gifts are a cover up. For political reasons, this makes sense. In this scenario, I could picture William Minerva being a part of a group who know the truth, and need the kids from Neverland as evidence (they'd need more than just the kids I presume, but the kids would be the smoking gun).
- The human gifts are known to all. This means they live with the shame of what their predeccesors did, and presume that all the humans were eaten after the great war. Then they find out the kids are alive somehow and things move from there.
- Perhaps a more thought provoking scenario is that the human gifts are known to all, and human farming is known to all (which niichan suggested in the OP). If we think to our own histories as humans (individually and as a society), much has been done in the past that we have to live with but cannot change. The humans in Neverland, under this scenario, have a chance to make up for the past. I do find this unlikely based on centuries of neglect.
Personally, I think option 1 is most likely. An alternative to the first scenario, in regards to WM, is that he's a part of the government and is rescuing the kids to prove to the public there are humans on the demons side... so they must go to war (this can fit in the second scenario as well).
Why go to war? I have no basis for it so far, but we go to war for resources and land. In this manga, farming has been shown on the demon side. For us, cattle and crops take up a heap of land. The Promise halved it. And from what we've seen on the demon side, the only structures we've seen are at HQ... which could mean the rest of it is 'untouched'. Well, Sung-Joo says there is
nothing but wilderness. And judging from the toys/items Ray procured, their human industry seems to be similar to ours. So this could work out too imo.
Didn't mean for this to be such a wall...