Chindogu

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.

See some more examples here. Official website here.