Family-based residence in Japan splits into two statuses that get confused with each other constantly:
Spouse or Child of Japanese National. For foreign spouses (and children) of Japanese citizens. This status carries no restriction on work — holders can take any job, same as a Japanese national, and it's one of the more direct paths toward long-term residence.
Dependent. For the spouse or children of someone holding most other visa types (a work visa or student visa, for instance). Dependent status ties your residence to the primary visa holder's, and work rights are limited unless you separately apply for permission to work part-time, similar to the student visa's part-time work permission.
Both require proof of the relationship (marriage certificate, birth certificates) and, in the Dependent case, proof that the primary visa holder can financially support you — see Financial & Income Requirements. Marriages that appear to exist mainly to obtain a visa draw close scrutiny from Immigration, so genuine cohabitation and a documented relationship history matter in the application.
If the relationship ends — divorce or the primary visa holder losing their status — the dependent's residence status is affected too, which is worth planning around well before it becomes urgent.
Spouses of Japanese nationals also qualify for a shortened route to Permanent Residency. Back to Visa Types.