It did explain one bit which I knew had to be some Japanese folklore I didn’t know. The rest I dk. I agree the overall plot is simple, it’s just the details I do not understand and felt there must be more back story from folklore or something which took away from the experience. Other Gibli movies like ponyo or howls moving castle didn’t leave me as confused on why they chose to show the audience something.
That’s fine though, 10,000 Years of unguided human history got us here. We relatively just got started in science. It would be more scary if we saw derelict super structures.
They had lead in baby power at one point. I also think they did some unethical stuff with baby formula in South America but I might be wrong. Someone correct me!