http://www.jca.apc.org/stop-shikei/epamph/dpinjapan_e.html
5.2 Process leading to the execution
5.2.1 Before the execution
The prisoners, their family members, or their counsels will never be informed in advance of an execution. On the morning of the execution, prisoners will be called suddenly and informed that "the sentence of execution will now be carried out," and will be brought to the execution chamber. Prisoners will not permitted to say goodbye to their family members.
They will not be able to call their counsels and will not be given opportunities to have legal assistance.
The fact that executions are not known in advance makes the prisoners' condition of mind unstable. These days, executions are carried out 6 or 7 years after confirmation of the death penalty sentences. This situation forces prisoner who have spent 6 or 7 years after confirmation of their sentences to live each and every day in dread of the day the execution will be carried out. Some people are executed even though they are appealing for a retrial. Even if prisoners are appealing for amnesty, they may be informed of their executions at the same time they receive notice of rejection of their appeal.
If prison officers stop in front of a cell in the morning, it means the last moments of the prisoner's life have arrived. Even if prison officers do not stop this morning, who knows about tomorrow? In that case, we may say that each new day merely gives prisoners a 24-hour postponement of execution. Such a life continues until the day of execution.
5.2.2 Execution of the death penalty
At the execution chamber, the authorities perform certain ceremonies. A few minutes are given to the prisoners for writing their will and for saying goodbye to their chaplains.
Then they are handcuffed from behind, blindfolded, and brought onto the hanging place, whose floor is split in two. They are tied up while on their knees to prevent wounding the body in case they struggle. At the same time the hanging rope is placed around the prisoner's neck.
At a signal, the floor splits into two, and prisoners fall into the opening. Since the length of the rope has been adjusted in advance to take account of the height of prisoners, they continue cramping until their death, suspended in the air some 15 centimeters above the underground floor.
In the underground room, a doctor is standing by to take the prisoner's pulse and listen for a heartbeat. It is said that 15 to 20 minutes are needed to die.
After the execution, the prisoner's family will be informed about it. If within 24 hours the family asks to have the body, it is possible to comply. There have been 39 executions since March 1993 when the execution of death penalty was restarted, but on only two occasions were the bodies taken back. Mr. Norio NAGAYAMA was executed in August 1997. His lawyer wanted to take the body, but the authorities had it cremated and only allowed his bones to be taken. It is presumed that there were traces of NAGAYAMA's final struggling.
Belongings of the prisoner are returned to his family, except for "diary or documents as such" after confirmation of his death sentence. There is no way to identify belongings, however, other than a "diary."