Private preparatory schools (yobikō 予備校) provide education for high school students and rōninsei (浪人生)—high-school graduates who have failed university entrance examinations at least once and are studying to take them again. The education through preparatory schools includes both classroom-based teaching and correspondence courses. Unlike ordinary high schools, which offer education for a range of purposes, the education at preparatory schools is dedicated to preparing students for university entrance examinations.
Students are admitted to universities in Japan through either a general, test-based admission system or a recommendation system. Preparatory schools focus on preparing students for general admissions. For the general admissions, all national universities and some private universities use a common university entrance examination called the National Center Test (daigaku nyūshi sentā shiken 大学入試センター試験), commonly known as sentā (センター) among students. Some universities also have a second-stage admission system, in which students who have received sufficiently high scores on the National Center Test are eligible to take the exams prepared by those universities. Private universities that do not adopt the National Center Test generally use their own original entrance examinations, though some accept scores for TOEIC, TOEFL, and other standardized tests. Most programs and courses provided at preparatory schools are therefore designed based on the National Center Test and the universities’ original examinations.
According to Toshihiko Maita, a blogger, about 24,000 students are currently enrolled at some form of private preparatory school, but the number has been decreasing due to the low birth rate and the recession (Maita, 2012).
Because the current university entrance examinations for English focus on reading (MEXT, 2014), English education in preparatory schools is also weighted toward reading. The courses at many preparatory schools are frequently based on collections of tests from previous years (kako mondaishū 過去問題集) or similar materials. This trend, however, may change in the near future, if the English components of university entrance examinations are replaced by exams created by institutions outside universities, such as TOEFL, TOEIC, or IELTS. Those examinations are intended to balance measurements of students’ four skills—reading, listening, writing, and speaking—and the education at preparatory schools would presumably adapt accordingly.
Maita, Toshihiko (2012) Decrease in the number of students at private preparatory schools (J) △ 舞田敏彦「予備校生の減少」『データえっせい』2012年3月1日木曜日 (Data essay)
Ministry of Education, Culture, Sports, Science and Technology (2014) The meeting of advisors on English education The document for the subcommittee on English ability assessment and introduction of the examinations made by institutions outside universities: How to introduce the examinations made by institutions outside universities to the university admission system (J) △ 文部科学省 (2014) 英語教育の在り方に関する有識者会議 英語力の評価及び入試における外部試験活用に関する小委員会配布資料「大学入試に外部試験を導入する現実的方法」(MEXT Website)
Ministry of Education, Culture, Sports, Science and Technology (2014) The meeting of advisors on English education The minutes of the second subcommittee on English ability assessment and introduction of the examinations made by institutions outside universities (J) △ 文部科学省 (2014) 英語教育の在り方に関する有識者会議 英語力の評価及び入試における外部試験活用に関する小委員会（第2回）議事録 (MEXT Website)