Visa application- maiden name on degree

I've been offered a job in Japan :D.

I'm hoping someone can help me out by answering this question:

What extra documentation will I need to apply for my work visa (specialist in humanities) due to the fact that my degree certificate is in my maiden (pre marriage) surname? My passport is in my married name and I've been married 5 years.

Thanks for your help!

Marriage certificate or something that proves you changed your name legally.

Marriage certificate or something that proves you changed your name legally.
A marriage certificate is not a legal change of name in most countries - it is simply a convention where people take another name, and it is accepted. But legally, the name is not actually changed and people are free to use either a maiden or married name.

As for what you should do for your CoE application is provide all of the documentation such as copies of passport, birth certificate, copies of degree and logically a copy of marriage certificate. It is very common for people to have documents under different names, even with out a formal, legal change.