Address for national leaving Japan for a year

Hello, I'm not sure if this is the right place to ask.

My partner is a Japanese national who currently rents an apartment in Tokyo. They would like to travel outside of Japan for a year with me but do not want to continue paying for their apartment that won't be used. I don't think it's legal to not have an address on file for pension and insurance purposes but I'm not entirely sure what someone would do in this situation. Is the only option to continue paying for housing that won't be utilized?

Thank you for your time and let me know if you need any more information.

why doesn't your partner ask the city office staff ?
they will explain him/her in detailed.
he/she can change the address to his/her parents house, too.

"I don't think it's legal to not have an address on file for pension and insurance purposes"
unsure, what do you intend ?

he/she can do it.
1.pension paying, health insurance not paying.
2. pension paying, health insurance paying.
3. pension not paying, health insurance not paying.
it is probably illegal that No.4. pension not paying and health insurance paying.

most Japanese choose either No. 1 or No.3.
city office needs his/her address, when he/she joins either pension or/and health insurance. so, he/she can move the address to his/her parent's house.
also, he/she needs to pay all resident tax of this year and file this year's income at city office. so, in any way, he/she needs someone who can manage it.

When i was young and went out on a year-long overseas assignment, I had to keep a registered address somewhere in Japan because I was getting paid by a Japanese company who sent me outside Japan. So i terminated my apartment rental agreement, moved my registered address back to my parentsf address. I was physically away for a year, and I had to pay the pension, health insurance, taxes, etc. for that year.

Your friend gcouldh remove themselves completely from their gjuminhyoh (resident record) as living overseas. And they can choose not to make pension or health insurance contribution. But for pension that means they lose one year of contribution, thus slightly less pension benefits later.

But this is done more by people who gmoveh overseas, like studying abroad, or getting a completely overseas work assignment (not like what I had, but getting paid by a non-Japanese entity), who will have an address they can register with the destination countryfs embassy.

Probably leaving the address at their parentsf might be a better idea for traveling, because gifh they return once temporarily to Japan and happen to want to go to a doctor, they will have insurance coverage.