noun
solitary confinement in a dark cell without bedding (up to one week)
A severe disciplinary punishment in Japanese prisons, involving isolation in a dark, bare cell for up to seven days.
重屏禁は、刑務所内で最も厳しい懲罰の一つとされている。
Solitary confinement in a dark cell without bedding is considered one of the harshest punishments within prisons.