In S.Korea and Japan, competition among schools or preparatory schools is so intense that three can be illegal cases.
For example, my boss, who works at my preparatory school, doesn't have enough holidays written on guidelines for job applicants.
According to the guidelines, each worker in my preparatory school must have 110 holidays a year. But, my boss said "I will never be off duty on weekdays." When I consider that she usually has to work on Saturdays, her holidays must be less than 110 days.
Because of decreasing population in Japan, preparatory schools will have to hire employees in more severe environment.