Dear All!
The high occurance of suicide in Japan seems, at least partly, to be linked to the particular status of suicide in Japanese culture. Not least, the ritual suicide commited by the famous Japanese writer Yukio Mishima in 1970, illustrates the aesthetics of blood and martyrdom in the name of Japanese greatness (see interview with Akihiro Miwa in an earlier posting).
In Himeji-Castle, for example, a place that is dedicated to ritual suicide is to be found within the castle walls, with a well to wash the bodies of the beheaded.
Evelin

From http://www.fastload.org/se/Seppuku.html:
Hara-kiri (also called seppuku) is a ritual and honorable suicide with Japanese origins. Traditionally, it is done in a spiritually clean temple by cutting open one's abdomen with a wakizashi, thereby releasing the soul. The traditional form is one deep cut down and one across. A slightly less honorable version (and much less painful) is that at the same time, a friend (called kaizoe[?] or kaizoe-nin[?]) severs the head for an instant death.
Hara-kiri was traditionally used as the ultimate protest when one's own morals stood in the way of executing an order from the master. It was also permissible as a form of repentance when one had committed an unforgivable sin, either by accident or on purpose.
In Japanese, hara kiri (腹切り) is a slang term -- literally, "belly slashing". The formal term for honorable suicide, which should be used unless one is deliberately trying to be insulting, is seppuku (disembowelment) (切腹).

From http://victorian.fortunecity.com/duchamp/410/seppuku.html:
Seppuku, (Sape-puu-kuu) the Japanese formal language term for ritual suicide (Hara-kiri (Har-rah-kee-ree) is the common language term.), was an intregal aspect of feudal Japan (1192-1868). It developed as an intregal part of the code of bushido and the discipline of the samurai warrior class.
Hara-kiri, which literally means "stomach cutting" is a particularly painful method of self-destruction, and prior to the emergence of the samurai as a professional warrior class, was totally foreign to the Japanese.
The early history of Japan reveals quite clearly that the Japanese were far more interested in living the good life than in dying a painful death. It was not until well after the introduction of Buddhism, with its theme of the transitory nature of life and the glory of death, that such a development became possible.
To the samurai, seppuku--whether ordered as punishment or chosen in preference to a dishonorable death at the hands of an enemy--was unquestionable demonstration of their honor, courage, loyalty, and moral character.
When samurai were on the battlefield, they often carried out acts of hara-kiri rapidly and with very little formal preparation. But on the other occasions, particularly when it was ordered by a feudal lord, or the shogun (as was directed of Lord Asano in the Tale of the 47 Ronin. ) , seppuku or hara-kiri was a very formal ceremony, requiring certain etiquette, witnesses and considerable preparation.
Not all Japanese samurai or lords believed in, even though many of them followed the custom. The great Ieyasu Tokugawa, who founded Japan's last great Shogunate dynasty in 1603, eventually issued an edict forbidding hara-kiri to both secondary and primary retainers.
The custom was so deeply entrenched, however, that it continued, and in 1663, at the urging of Lord Nobutsuna Matsudaira of Izu, the shogunate government issued another, stronger edict, prohibiting ritual suicide. This was followed up by very stern punishment for any lord who allowed any of his followers to commit harakiri or seppuku. Still the practice continued throughout the long Tokugawa reign, but it declined considerably as time went by.
Honor for the samurai was dearer than life and in many cases, self destruction was regarded not simply as right, but as the only right course. Disgrace and defeat were atoned by committing hara-kiri or seppuku. Upon the death of a daimyo loyal followers might show their grief and affection for their master by it. Other reasons a samurai committed seppuku were: to show contempt for an enemy; to protest against injustice, as a means to get their lord to reconsider an unwise or unworthy action and as a means to save others.
The ritual for disenbowlment was to be performed calmly and without flinching. If condemned to death, it was held to be a privilege to execute the sentence on one's own body rather than to be a disgrace and die at the hands of the public headsman.
The location of an officially ordered seppuku ceremony was very important. Often the ritual was performed at temple
(but not Shinto shrines), in the garden or villas, and inside homes. The size of the area available was also important, as it was prescribed precisely for samurai of high rank.
All the matters relating to the act was carefully prescribed and carried out in the most meticulous manner. The most conspicuous participant, other than the victim, was the kaishaku (kie-shah-kuu), or assistant, who was responsible for cutting off the victim's head after he had sliced his abdomen open. The was generally a close friend or associate of the condemned.
Although suicide is deplored in Japan today, it does not have the sinful overtones that are common in the west. People still kill themselves for failed businesses, involvement in love triangles, or even failing school examinations, death is still consider by many as better than dishonor.

From http://www.oren.jp/japan_12.htm:
Seppuku means the ritual form of suicide that used to be practiced by members of the samurai class to show they accepted responsibility for their actions. It has its beginnings in the Heian Period, about one thousand years ago. In present-day Japan, of course, seppuku is not practiced either as a form of suicide or as a punishment.
In Japan, a man who is respected as being a person of high moral character is said to "have stomach", meaning that he is a man of definite principles.
In feudal times warriors used to respect the abdomen because it was considered to be the receptacle of the spirit, so when they assumed responsibility as warriors for some action or course of conduct and had to die, they would cut open their abdomen.
In the Edo era seppuku became the mode of capital punishment for members of the samurai class. To allow the warrior to die by his own hand showed respect for his character and honor. To avoid mishaps occurring during the act of seppuku and to cut short needless suffering, another person would be standing by to cut off the head of the person as soon as he had cut open his abdomen.