A note from the Kumamoto International Desk of Bureaucratic Stuff One Learns Too Late (pay attention!): When my son went bye-bye to study in America, we duly severed him from our health insurance and left him to his own devices (Obamacare!). When the same happened with our daughter, we continued paying her premiums as we worried that her asthma might require medical treatment during her brief visits home.
Here is where it gets interesting.
When my daughter turned 20, demands for payment to the pension system began to arrive, while they never did for my son - it turns out that health insurance and pension are connected, you see. So my son is invisible to the system (ironic, as he now lives in Tokyo); meanwhile, my daughter has racked up $1,800 in pension fees despite having no job and living in the US. I continued to toss statements into the bin until the most recent, which gave me pause: It stated that they could resort to confiscation in lieu of collection.
This was totally fine with me. I mean, my daughter is an adult, so I have no legal responsibility for her, and if they want to confiscate stuff - look at her room! It’s littered with unwanted underwear and whatnot. They’d be doing me a huge favor by confiscating as many of her assets as they could get their hands on.
But I’m a bit more responsible than that (the urge was there for a moment, though), so I visited the tax office, where I was politely informed that she would be exempt from pension payments until she’s 23 (and this also cancelled the $1,800 they’d claimed, which means I’ll have to clean her room by myself) - the age when one must choose a nationality under Japanese law.
So there you have it. If you are the parent of a dual-national child and remove them from health insurance, should they move abroad, they will not be automatically enrolled in the pension service. If they are enrolled, even if they are abroad, they will. (The insurance clerk told me we may receive continuing correspondence demanding payment or confiscation for some period, so perhaps there is still hope. Otherwise, I’ll have to clean my daughter’s room myself.)