Seppuku is a form of Japanese ritual suicide by disembowelment. It was originally reserved for samurai in their code of honor but was also practiced by other Japanese people, later on, to restore honor for themselves or for their families.
As a samurai practice, seppuku was used voluntarily by samurai to die with honor rather than fall into the hands of their enemies (and likely be tortured), as a form of capital punishment for samurai who had committed serious offenses, or performed because they had brought shame to themselves.
The ceremonial disembowelment, which is usually part of a more elaborate ritual and performed in front of spectators, consists of plunging a short blade, traditionally a tantō, into the belly and drawing the blade from left to right, slicing the belly open.
If the cut is deep enough, it can sever the descending aorta, causing a rapid death by blood loss. The proper method for committing the act developed over several centuries was to plunge a short sword into the left side of the abdomen, draw the blade laterally across to the right, and then turn it upward.
It was considered an exemplary form to stab again below the sternum and press downward across the first cut and then to pierce one’s throat.
Being an extremely painful and slow means of suicide, it was favored under Bushidō (warrior code) as an effective way to demonstrate the courage, self-control, and strong resolve of the samurai and to prove the sincerity of purpose.
Women of the samurai class also committed ritual suicide, called jigai, but, instead of slicing the abdomen, they slashed their throats with a short sword or dagger. There were two forms of seppuku: voluntary and obligatory.
Voluntary seppuku evolved during the wars of the 12th century as a method of suicide used frequently by warriors who, defeated in battle, chose to avoid the dishonor of falling into the hands of the enemy.
Occasionally, a samurai performed seppuku to demonstrate loyalty to his lord by following him in death, to protest against some policy of a superior or of the government, or to atone for failure in his duties.
