More correctly,
seppuku....here's a step by step guide to it (albeit a very sarcastic one):
Seppuku - A Practical Guide.
By Nick May
It is hanami time in Japan and readers thoughts turn naturally to ritual disembowelment. Here in handy cut out form is the Gleaner guide to elegant self-immolation - please don't call it hari kiri...
Seppuku is highly ritualistic, exquisitely precise and earns you maximum respect from students and potential job interviewers alike. However, to avoid excessive pain, thoroughly internalise this fact: seppuku is all about RITUAL. Often one was not even required to DO anything, merely reaching for the knife was considered to be the act initiating your second's coup-de-grace. In almost all cases death occurred from having the head almost separated from the body.
Obviously you have to decide well in advance why you are doing it as precise etiquette varies. Resistance, remonstrance, show of loyalty, affirmation of the correctness of one's own position, expiation of a crime and the wiping out of disgrace are all perfectly good reasons; being refused a work visa is not (though it might come under funshi, or seppuku to express great indignation). After all, even in matters of self disembowelment a man must retain a sense of proportion. We will discuss "basic" seppuku and leave you to furnish your own flourishes.
Seppuku absolutely requires a minimum of two participants. Waiting to die from disembowelment is a notoriously drawn out process, very messy and trying for the spectator. Since the Empo era (late 17th century) only loonies such as Mishima and characters in Samurai dramas actually waited for hours to contemplate their entrails by- the-light-of-the-rising-sun - there is no need for you to indulge in anything so vulgarly melodramatic. You will require the services therefore of a Kaishakunin, or "second" whose duty it is to despatch you with a sharp sword at your signal. The exact moment he strikes is entirely for you to decide - obviously the later and more painful your death the better your chances with that next visa. For maximum effect and minimum pain we suggest you fake it. Be sure however that your second has no higher ideals than you, and of course better nerves and swordsmanship.
Choosing an appropriate Kaishaku-nin is obviously very important. You should consider the following. Beheading being very infra dig points are deducted for actually detaching the head. Make sure your kaishakunin has practiced and perfected the "daki-kubi" cut so that your head is left attached to the body by a short flap of skin. This ensures your face is hidden, demonstrates his prowess with a sword and entirely remove the stigma of decapitation.
There are three ritual systems indicating when it is appropriate to strike; choose the one most appropriate to you. Do chat to your kaishaku-nin beforehand and establish precisely when he is to intervene. DON'T rely on a student, in our experience they make lousy kaishikunin - they've all seen far too many samurai movies and read too few history books. They will almost certainly insist you not only disembowel yourself but write your name in kanji with your own blood on a silken handkerchief given-you-by-fair-virgin-lady before carrying out their ultimate duty. If you are a child, point out that it is customary to strike at the earliest possible moment. The knife itself, the kozuka, should be of about 11.5 inches, wrapped in paper with the final inch exposed. Check it is steel and not a painted bamboo substitute. Youth can be cruel.
Dress and execution. A loose kimono should be worn. As soon as the Sambo tray with the knife is placed before you, allow the kimono to fall open, reach forward, pull the tray toward you, pick up the knife and cut from left to right. The "jumonji", the crosswise cut, may be omitted by colonials but gentlemen will know better. The final upward jerk may result in a "summa cum laude"! Remove the knife, replace it carefully on the Sambo and signal the Kaishaku-nin to proceed.
In general your friends will try to create an atmosphere of mourning as though you are already dead. Don't be offended - this consideration is intended to put you at your ease! Immediately prior to the act you may be offered a last cup of water. Your cup will be filled in two pourings, you must drain the contents in two pairs of two sips. "Three" is taken to imply repetition, two indicating definitely-not-repetition-no-way! 2 X 2 is 4, or shi, which can be read as "death". How comforting such intellectual jeux d'esprit at this time!
And that is about it. DON'T engage in any of the degenerate forms of seppuku that involve stabbing yourself with a paper fan: they are vulgar and a paper cut can be quite nasty. DO cover the tatami in your apartment or your guarantors will have to replace it and definitely DON'T chew gum or ask for a last cigarette. Be considerate of others and try not to make a lot of noise.
The rules for seppuku are as complex as for the tea ceremony, and the result roughly the same; if pushed we would have to recommend self-disembowelment over a slow death from lethal boredom, arthritis and bitter tea.
http://kyushu.com/gleaner/editorspick/seppuku.shtml
Another discussion of technique:
The Fine Art of Seppuku
Seppuku (only gaijin refer to it as "hari-kari") is a highly ritualized performance, as complicated as tea ceremony or chado. The principle difference is that at the end of chado, one is merely nauseated from too much green tea, whilst at the end of seppuku, one is dead.
Seppuku is ideally committed by in a garden or a Buddhist temple (Shinto temples should not be defiled by death). The participant dresses in white, to express purity of intention and sits in the seiza position (legs drawn up under the body so that one is actually sitting on ones heels). A servant places the sanbo (an unlacquered wooden table) before one. It will contain a sake cup, a sheaf of washi (paper handmade from mulberry bark) and writing accoutrements, and the kozuka (disemboweling blade). This can be a tanto (dagger) blade without hilt, wrapped in several sheets of paper to provide a better grip. Real samurai, however, use their own wakizashi.
The sake cup is filled from the left, by an attendant using his left hand (this is indescribably rude under other circumstances). The person committing seppuku then empties it in two drinks of two sips each (one sip would show greed, whilst three or more would show hesitation). This makes a total of four sips; shi, "four", also means "death" (Nihonjin just love these kinds of puns, especially when theyre about to kill themselves).
One then writes a death poem in the waka style (five lines of five, seven, seven, five, and seven syllables). The poem should be graceful, natural, and about transient emotions. Under no means should it mention that the fact you are about to die. Asano, whose seppuku precipitated the famous "Forty-seven ronin" incident, is said to have written a particularly poor death poem, showing the immaturity and lack of character that led to his being ordered to commit seppuku in the first place.
At this point, the person slips out of his outer garment (kamishimo) and tucks the sleeves under his knees to prevent him from doing something undignified like slumping to one side. He picks up the kozuka, and with his other hand picks up the sanbo and places it under his buttocks, to cause him to lean forward slightly in the proper attitude.
If the person committing is so young or so evil that a fan has been substituted for a blade, the kaishakunin executes a kirioroshi strike (a vertical cut) as soon as the person committing seppuku touches the fan to his stomach. Otherwise, he will typically wait until the person plunges the blade deep into the left side of his belly, and draws it across to the right, with a sharp upward cut at the end. A samurai who feels himself capable may then plunge the blade into his groin and cut upwards to the sternum, followed by a horizontal cut at the base of the rib cage. However, the kaishakunin is supposed to keep a sharp (heh, heh) eye out, and strike at the first sign of pain or hesitation in his principle.
The kirioroshi, incidentally, was not intended to actually sever the head, but to leave it attached by a strip of skin at the throat. It was considered infra dig for ones principals head to go spinning across the room, spraying blood as it went; only low-class criminals were treated thus. Especially one should not whack ones principal in the jaw with the katana, as Yukio Mishimas kaishakunin did in 1970. The sanbo, the kozuka, and the katana are all discarded as being defiled by death.
Incidentally, real badasses did kill themselves, in the ritual known as jumonji giri. This is just like seppuku, except that there is no kaishakunin. After disemboweling yourself, you sat quietly and bled to death over the next half-hour or so. The last person to do this historically was General Nogi, who did it as junshi (following ones lord in death) on the death of the Meiji emperor in 1912. He not only committed jumonji giri, he buttoned up his white naval blouse afterwards.
In such circumstances, of course, there usually wasnt time for the whole ritual, so expedients as cutting ones own throat, throwing oneself from a running horse with a sword in ones mouth, or flinging oneself off high walls, towers, or cliffs were winked at.
In 1516, Muira Yoshimoto committed suicide by cutting off his own head, something that got him a gazillion style points (he was still dead, however).
SOURCE:
http://www.win.net/ratsnest/archive-articles21/fog0000000384.html