
Samurai commonly had to get permission to perform this act. After some time this suicide became a planned ceremony. The ceremony was usually performed in front of spectators and was originally used to avoid capture by the enemy, but was extended to the use of dying honorably despite previous shame.
The sword that is used for the ceremony is called a tanto, which is a sword used by samurai. In the ceremony, the samurai would recite a death poem, then plunge the tanto into the stomach and cut from left to right. After this happened, another person would tilt the samurai's head back and slice so that just a flap of skin held the head on.
This practice was abolished in 1873 as a form of judicial punishment, however there have been several acts of seppuku that followed. Some of these include civilians and soldiers who did not wish to surrender after WWII, and Yukio Mishima who committed seppuku after failing to convince authorities to overthrow the government.