Highschool in Japan age limit?

I was wondering if someone could attend high school in Japan at 18 or 19 before they do college.

The answer is yes, as long as you haven't graduated another high school. In fact, 18 is the minimum age to graduate high school in Japan and one can attend start high school at any older age, whether you're 99 or 121.

If you've already graduated a senior high school, however, please discuss with the high school you wish to attend or its board of education. You may need to apply for special programs in that case.

By the way, senior high school is not compulsory education in Japan, so every high school has some kind of entrance exam to see if the applier is qualified for the school.

So does that mean to get into a highschool in Japan, you could not have graduated any high school in Japan already? Or does that mean any highschool in the world. I have heard of a few people who went to highschool there after graduation in their home country.

Once you have completed your secondary education in or out of Japan, you are not permitted to study back in a high school in Japan. Because you have already completed the course.

Preparatory classes for University or cram schools could be the place to enter for University if you are a high school graduate.

Austin,

The basics are as tokyo friend 48 wrote, but again, there are many possibilities.

For example, people graduate school in the U.S. in June, while in Japan they graduate in March of the next year. So, often Japanese returnees will talk to their new schools to see if they can get a transfer (again, granted they have the proper academic skills to keep up with studies in Japan). Or foreign students may get a chance to participate in exchange programs of some kind.

Anyway, you should pinpoint some schools you want/need to go to and contact them for more details. Schools also often have that kind of information printed on their websites.