Regarding the signature certificate, I tend to sign not my full name, but a nickname. Would this be a problem?
★ Explanation ★
A signature certificate is a type of document issued within Japan than can be used instead of a certificate of seal impression. If one does not reside in Japan, and as a result, is unable to obtain a certificate of seal impression, there are various processes that would let one use a signature certificate instead.
A signature certificate does not require that one’s signature be uniform and relevant to one’s real name, so there is no problem with using a nickname or alias as their signature. On the other hand, one’s registered seal must abide by specifications provided by the law, such as size, clarity, and uniformity with one’s real name.
The signature certificate needs to be authenticated by the notary office as the document implies that the sign indicated in the signature certificate is indeed the person’s signature. For example, a person named Wang Li-bai could use the nickname “John”, and if he shows sufficient proof that he goes by such a name, then there should be no repercussions should he use “John” the signature he affixes on his signature certificate. On the other hand, if the person attempts to use “Wang Li-bai” in a signature although “John” is the name indicated in the signature certificate, such signature would not be recognized.
When incorporating a company, those who would become the incorporators or executives of that company must submit either a certificate of seal impression or a signature certificate. When doing processes with notary offices and legal affairs bureaus, it is important that the signatures in the signature certificate as well as the signatures affixed in the submitted documents are one and the same. As such, be careful not to affix a signature that isn’t a certified signature in documents.
As mentioned above, the signature certificate is used in Japan as a substitute for the Japanese seal certificate, and in principle, the uniformity and relevance of the signature with one’s real name described in the signature certificate are not required.