A study says that nearly half of young men and women in Japan are still virgins.According to The Japan Times , the National Institute of Population and Social Security Research (NIPSSR) surveyed 8,754 single people and 6,598 married couples for its annual study, which looks at household, relationship, and birth rates.The survey results reported that of people aged 18-to-34, "around 42% of the men and 44.2% of the women admitted they were virgins." The newspaper reports that those numbers are actually higher than they were in 2010.While it isn't an exact comparison, in the United States, according to the Center for Disease Control's most recent data , the mean age at first sexual intercourse for females is 17.2 years.For males, the number is only slightly lower at 16.8. Both of those are younger than the 18-to-34 demographic interviewed in Japan. As for pre-marital sex , the CDC data says that 89.1% of females aged 15-to-44 and 91.8% of males aged 20-to-44 reported having sex before marriage.So really, it's not that no one is having sex in Japan, people just aren't having that much of it. That's what concerns the researchers. Japan faces a decline in birth rate combined with an ageing population.Other data from the Institute's annual studies shows that the "ideal number of children" desired by both married couples has also been in decline