Adding non-family to juminhyo

A little while ago, I asked a question about this, and I wanted to update just in case the information is useful to anyone:

I have a same-sex partner and child (that she gave birth to) that I recently added to my juminhyo. It now lists me as the head of household, and they are listed on the document. The process was easy - just apply at the ward office.

The only consequences of this change, that I have discovered so far are:

• I now get the bills for their national health insurance premiums (partner is unemployed). The premiums are based on my salary now (or I assume, combined income), thus the monthly premium we pay has increased by about ¥11,800.

• After submitting the new juminhyo to my employer along with our partnership certificate issued by my municipality, my employer gives me a dependent allowance for my partner of about ¥15,000. They are still deliberating about an additional allowance for the child, but it is possible they will give me that as well.

• My partner’s single parent benefits from the family welfare section remain unaffected.

Note: The benefits from my employer are specific to my employer, so if there are no benefits of this sort, it is likely not a good idea financially to make this change as premiums may go up.