A. You must apply for a short-term visa for your parents.

A short-term visa is said to be a so-called "tourist visa", but it is intended for activities such as sightseeing, recreation, sports, family visits, tours, lectures, participation in meetings.
Wedding ceremonies, etc. fall under the family visit.

For short-term visa, there is a country where visas are exempted only by having a passport. For details, please look at this homepage.
If it falls under that country, you can enter Japan as a short-term visa with no visa application, so if you have a plane ticket for returning, you do not need to apply for the immigration office.

However, due to such questions, China, which is the most likely country, can not enter Japan with No Visa.

In order to call Chinese parents to a wedding ceremony, the following documents are required and the standard period for judgment is one week. For details, please see this homepage.

· Personal certificate of guarantee and guarantor's job certificate, income certificate, taxation certificate, tax payment certificate, final return etc.
· Applicant list (for parents)
· Stay schedule
· Certificate of resident cards of both people marrying
· Copy of residence card
· Proof of reservation at wedding palce
· Visa application form
· Parents photos and passport
· residential certificate · Relationship notarization letter