High school is not compulsory in Japan, and even public high schools require tuition fees. In Tokyo, students have to pay a little more than ¥10,000 a month to attend public high schools. That may not sound like much, but they also have to take a test to get into these schools. If they fail and want to continue their education then they have to attend a private high school, which are, needless to say, more expensive than public high schools — and easier to get into. Basically, all you have to do is pay.
It's an unspoken but generally held belief that private-school students are on the whole scholastically inferior to public-school students. Parents with enough money will send their kids to cram schools at an early age, thus ensuring that they can pass the test to get into a public high school (and, later, a national university), while kids from less affluent families are not able to afford cram schools and thus end up attending private schools, where they have to spend a lot of money in order to graduate. And with more parents losing their jobs due to the recession, more teens are not going on to high school simply because they cannot afford to.
You can read the whole article here.
Remember, ¥10,000 roughly US$100, so that's not a whole lot. And I know that American high schools have extracurricular fees, so they are not entirely "free".
Perhaps, this does help the higher achieving students. They are not dragged down by standards that must slow down a bit for students who, due to ability or attitude, will not meet higher standards. And students can choose among many high schools to try to get into, not just the one in their town or section of town. At least one of my students was planning on boarding while attending high school. It's like charter schools here -- different ones specialize in different areas or different academic levels.
Some are connected to a particular university, and have such high academic standards that their graduates don't have to take the entrance exams for that university. And some of those high schools have affiliated junior high schools, grade schools and kindergartens. A kindergarten entrance exam that will get you into a top university later in life -- no pressure there, huh?
And lest you think those that don't go to high school are being too short-changed, remember that Japan has a higher literacy rate than the US, despite having the most complicated writing system on the planet. Plus, they will have sat through 3 years of foreign language instruction (English). Since Japan has a 6-3-3 system, the end of junior high school is a 9th grade education in the US. So, their American counterparts have optionally likely had 1 year of a foreign language. Those who don't go to high school can start apprenticeships if that is what their career path requires.
Overall, I am still kind of amazed at this system. Given the importance that East Asian cultures, including Japan, give to education I was stunned that high school was not required. But the system seems to work, and it keeps the 3rd year students in junior high school focused. SAT's aren't 3 years in the blurry future -- they are now!