Tsukumogami 付喪神

In Japanese legends, certain tools and common household items are said to be able to acquire a soul or spirit, and cause evil or mischief. Called Tsukumogami, these spirits were originally thought to come alive after 100 years, and seek revenge on people for neglect and disuse.

Woodblock print, A New Collection of Monsters

Tales of the tsukumogami became popular in the Middle Ages, and people took precautions to keep their possesions from becoming monsters. Often folks would throw away items before they reached a century, or have special ceremonies performed to propitiate the spirit.

Hokusai, The Lantern Ghost

When Shingon Buddhism was being spread in the 10th century, monks used the tsukumogami myths to exemplify their teachings and make the difficult precepts more accessible to peasants and nobles alike. By modern times, belief in these creatures has become more of a cultural tradition than actual belief, and the tsukumogami tend to be thought of as harmless pranksters, and the tales encourage people to not be careless or wasteful with their things, probably contributing to the minimalist lifestyles of many Japanese.