Whether or not you have lived in Japan long term or short term, or perhaps even just visited briefly, you are probably aware that in Japan people use a personal name stamp in place of signing their name by hand. There are several different kinds of name stamps, called INKAN or HANKO in Japanese, which are used for different situations.
Individuals have them, even organizations and companies have them. This is less true now than it used to be, but you cannot complete a contract in Japan without stamping it in multiple places with “your inkan.” Big things, like signing for a bank loan, will require stamping with an “official inkan,” which are registered at the city office and are used for contracts and legal documents.
Most of the time, however, life in Japan calls only for “your inkan.” Normal stamps are not registered anywhere, and are used in place of a signature. These are generally hand carved wood and can be very expensive or very cheap. The more expensive the stamp is, the harder it is copy (theoretically, anyway!=) If you have a Japanese family name, these inkans can be easily found at most stationary and book stores. If not, then you need to have one made.
For most foreigners living in Japan, an official registered inkan is not really necessary, but a personal inkan can come in handy. This type of inkan is specially made with the individual’s last name. It is not registered and is used for stamping “day to day” forms, and other official documents that do not require a registered inkan. For example: the application used to open a bank account or setting up auto payments for utilities.
You can also buy self-inking inkans, which are made of rubber and are used for a wide range of things such as signing for a package being delivered or signing off on memos and notes being passed around an office. If you are Japanese you probably own several of these, along with an official registered family inkan.