OK. I like the artwork.
I haven't finished this first installment, but I do wish to continue reading it. It's a unique situation, in scale, at least. Kind of like the opposite of "Gate".
One issue of note (maybe it shows up later in the chapter) is that Japan is not known for its natural resources. It is particularly dependent on foreign oil. I would say that the government, once it gets an idea of the scope of the country's situation, would institute immediate cessation of all unnecessary transportation, and severe cutbacks in electrical power. I suppose they can re-start some of their nuclear plants. (Oh, hey! Fukushima is still leaking steadily, isn't it?) I also don't know how well Japan is situated for other minerals, such as metal ores, but they took over China, etc back in the 20th century because they were desperate for raw materials.