The author is so baaaaaaaad at writing.....

It makes
ZERO sense why a Japanese land god got suddenly mad with such reasons in this time frame, but not during WWII....
War? Some parts of Africa, the Middle East, Afghanistan or russia, maybe North Korea would make sense, but not Japan.
Infestation? Exploiting nature? Again, some parts of Africa or russia, in addition of China, India, the deforestation in the Amazonas, or the USA, but not Japan.
In the past, multiple generations before? Yes.
But not in the current time frame.