Updated: May 15, 2021
Chindogu was created by Japanese artist Kenji Kawakami in the 1990s, who describes these inventions as "un-useless." He coined the term chindogu using a combination of the Japanese words chin, meaning "strange" or "odd," and dougu, which means "device" or "tool." But chindogu is more than a mashup of words (a portmanteau, if you will); it's a philosophy.
There are 10 tenets of chindogu, according to the chindogu society:
A chindogu cannot be for real use.
A chindogu must exist. No thought experiments allowed.
There must be the spirit of anarchy.
Chindogu are tools for everyday life.
Chindogu are not tradeable commodities.
Humour must be the byproduct of a chindogu.
Chindogu is not propaganda.
Chindogu are never taboo.
Chindogu cannot be patented.
Chindogu are without prejudice.