ok so lets look at so maths i dunno what the point is but i wanted to do it
Ok so, Japan has an estimated Population of 126,476,461 and ratio of 95.55 males per 100 females in which means 48.5% of the Population is male 61.7m
so now in one of the chapters it said around 22m males had died, and ofc that has increased so lets say 24m
617k is 1% now into 24m its roughly 40%, 40% of 48.5 = 29.1% of the total pop is now male
the ratio has now gone down to nearly 2 males to 3 females, let say this ratio is the consenting age and stuff
but given enough time that ratio will go up, stagnate then Crash, which would basicly Kill Japan within a few years as the Mortality rate is bascly 1000 deaths to 1 life.
whom ever wrote this Manga is an idoit and doesn't understand human interactions at all, every women displayed so far is a Stuck up cow, and all men are losers that are indecisive twats, there would be anarchy right now. there would be no pussy footing around