The earliest written evidence of cats in Japan indicates that they arrived, most likely from China or Korea, at least 1000 years ago. Unfortunately, we cannot tell from records whether these immigrants had bobbed tails or whether the mutationthat produces these tails first appeared in Japan. For hundreds of years bobtailed cats were highly valued and guarded, but in 1602 Japanese authorities decreed that all cats should be set free to cope with vermin which were threatening silk worms. Buying or selling cats was forbidden, and from that time forward bobtailed cats lived in the streets and on farms.