During the over 250 years of the Edo period, with the shogunate's rigid class system and laws, the number of ronin greatly increased. During previous ages, samurai were easily able to move between masters and even occupations, and marry between classes. However, during the Edo period, samurai were restricted from doing so, and were above all forbidden to become employed by another master without his previous master's permission. Also, low-level samurai, often poor and without choice, were forced to quit or escape their master.
Traditionally in Japanese culture, ronins were generally somewhat disreputable; a target of humiliation or satire. Their code requires the samurai to commit suicide or seppuku when they lose their leaders, or else afterwards suffer shame.
As an indication of the humiliation felt by samurai who became ronin, Lord Redesdale (British attache to Japan shortly after it was opened to the world during the Meiji Restoration) records that during his stay in Japan, when he lived two hundred yards from the graves of the Forty-Seven Ronin, a ronin killed himself at their graves. He left a note saying that being a ronin, and without means of honourably earning a living, he had tried to enter the service of the Prince of Choshiu, but was refused. That having been refused, he wanted to serve no other master, and being a ronin was hateful, so he had decided to kill himself, and what more fitting place could he find? Lord Redesdale reports that he himself saw the spot only a hour or two later, and the blood was still on the ground.
The term ronin is also used in modern Japan for those who failed the college entrance exam. This use probably derives from the analogy that they have no school to attend, as a ronin samurai has no leader to serve; there is also a parallel to the shame of the original ronin, in failing to pass the exam.