In Korea, until in the elementary school period, men and women treat each other as if they are friends of different gender rather than seriously thinking a way to fall in love. and since middle school, men and women are separated. (In Korea, men's and women's middle and high schools are mostly separated.) since then, they can't meet because both men and women students are busy with preparation for college entrance exams(SAT). After enter college, men and women on the same campus, then they already become an adult(with legal age), so there is no social or Circumstance restriction.