THAT STORY GOT IT WRONG PARTIALLY. japanese got too few in kid got NOTHING to do with NO SEXUAL CONDUCT, BUT UT'S RATHER the OPPOSITE,THE DESIRE THAT X-CONDUCT so much that if they marry and got kids will ELIMINATE their times and ENERGY to enjoy X so they just prevent having more kids to burden their PRECIOUS RESOURCES.
that X thing is NATURALLY BUILT in their genes LONG before they stick their heads to see/smell this PLANET so they can NOT GET RID of it. it' ONLY MONEY and RESOURCES LIMITATIONS that prevent JAPANESE to have more kids.