Believe it or not, Japanese University students start the activity of searching for a company to work for ("Shukatsu") more than one year before graduation.
Students start searching for their jobs in December of their third year. Graduation would be still one year and three months away (which takes place in March here), and the academic activities are at their peak. And yet, the students would be obliged to start the job searching right in the middle of the academic year.
The companies, on the other hand, do not usually consider those who have already graduated, or have spent some time away from an institution such as a university, as potential recruits. As a result, there is a tremendous pressure on the students to "stay on course". A gap year is not allowed. For example, if you want to work as a volunteer abroad after graduating from a university, it would usually signify that you would not be able to work for a company as a "regular employee" ("Seishain"), because only the freshly graduating students can be considered for that status.
Personally, I think all this is RIDICULOUS with a capital R.
Life is not a belt conveyor. People make random walks, and are well advised to do so, as they would learn lots of valuable things in wandering around. If you are managing the recruiting process of a company, it would be only sensible to look for people with various different backgrounds, as the survival in the competitive market today would require a diversity of talents, including those who are able to potentially support themselves independent of an institution.
The current Japanese custom, where the big companies consider only fresh graduates as candidates for employment, is not only foolish from economical point of view, but also, needless to say, constitutes a serious infringement of basic human rights. It should be rectified ASAP.