Rōnin and Yobikō

In Japan, a rōnin (浪人^?, ろうにん) is a student who has graduated from middle school or high school but has failed to enter a school at the next level, and consequently is studying outside of the school system for entrance in a future year.^[1][2] Rōnin may study at a yobikō.

The term "rōnin" is colloquial; the word kanendosei (過年度生^?) is more formal. "Rōnin" derives from their having no school to attend, as a ronin (a masterless samurai) had no leader to serve.
Sometimes the term 二浪 (sort form) or 二年浪人 (full form, 二年 - second year) is used for student, who failed exams twice.

Yobikō (予備校^?) are privately run schools that are marketed to students taking examinations held each year in Japan from January to March to determine college admissions.

These students generally have graduated from high school but have failed to enter the school of their choice.

This test, unlike the French Baccalauréat or the South Korean College Scholastic Ability Test, has different versions with different schools looking for results from different exams. In Japan, this test is generally considered the most important event in a child's education. Students who fail may spend a year or more studying to retake the examination. They are sometimes referred to as rōnin, after masterless samurai.