@no168_92 Yes they do. Although not Japan, I had to get close to perfect scores for secondary and junior college exams (equilvalent to high school). The style of the exam is similar, the mock exams in Japan is essentially a memorisation test. If you study hard enough, no reason you can't get a perfect score.
That being said, I also took SAT and several UK internal GCE as well, and found them laughably easy in comparison. There's something to be said about memorisation and it's role in enforcing a studious and knowledgeable foundation.