Japan has a local custom to use a Seal for formal documents and this is an inevitable custom for foreign entrepreneurs as well.
The Seal is called 印鑑 (Inkan) or 判子 (Hanko) in Japanese and we usually use this in place of using our own signature.
At the time of incorporation, a company has to make its own Corporate Seal and it has to be registered to the jurisdictional Legal Affairs Bureau where the head office of the company is located.
(We can also prepare for the Seal and this cost is included in our set menu for KK/LLC company establishment: Fees )
After the registration process is completed, a Seal Registration Card (Inkan Card) will be provided and the Seal Certificate can be issued by using the card. This certificate will be used in various situations, for example, opening a corporate bank account, making a contract officially, business licenses or financing, etc.
An important point to be careful is that the Seal Certificate is, in most cases, valid for only 3 months from the issued date (The expiry date is usually decided by each law or organization). This certificate can be issued any number of times, so you can just bring the Seal Registration Card to the nearest Legal Affairs Bureau to get the new one.