In the animistic tradition of Shintō all living and natural things are born or hatched or sprouted or formed
with souls, and even an artificial object can obtain a spirit of its own under the right conditions. While some special objects such as swords are created animate, most instruments and utensils must live, be used, and accrue virtue for a hundred years in order to obtain a soul. Once this happens, if they have not been treated well,
these objects can become vengeful bakemono. Called tsukumo-gami, these haunted utensils can partially take on the forms of monstrous humans, animals, and combinations thereof, and storm about the countryside tormenting people.

There are dozens of this particular kind of yōkai recorded, and the famous hyakki-yakō-emaki (hundred demon night parade picture scrolls) of the Muromachi era depict an extraordinarily creative assemblage of monsters derived from objects.¹

At least partially out of belief in tsukumo-gami, at the end of every lunar year Japan holds Susuharai, or "Soot Sweeping", a sort of ritual spring cleaning. Not only is it hoped that along with the accumulated dust, the haunting impurity will be cleaned away from the household's objects, but particularly old objects are
sometimes thrown away in an attempt to remove their dangerous potential from the house. Of course, being discarded often just makes the tsukumo-gami that much angrier.²

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1. Mizuki vol. 1 2003, p. 67

2. source