seppuku
Also known as hara-kiri, a form of ritual suicide by disembowelment. Primarily practiced by the samurai, seppuku was used to die with honor rather than falling into the hands of an enemy, as a means of punishment for serious offenses, as a means of protest against a lord's decision, or to atone for dishonor, such as a shameful deed or a failure to protect one's lord.
It was performed by the samurai using a tanto or wakizashi to cut open one's belly from left to right in a slicing motion, at which point the kaishakunin, the samurai's second, had the job of finishing the job by beheading him before he could show any sign of pain or loss of composure.