I'm a dual citizen; USA & Dutch.
I've worked in Luxembourg for the past 5 years. I was a cross-border commuter, living with my family in Germany (wife + 3 kids).
I've recently accepted a job in Japan. Our current arrangement is that I live in Tokyo, while my family remains in Germany. This situation is temporary, lasting anywhere from 6 to 9 months.
For tax reasons, it is best to register my family as dependents in Japan (see this site for an example calculation). If I register them as dependents, they would also be covered by the Japanese national health insurance.
Thing is, if they are insured in Japan, they'd have to pay all medical expenses in advance and send all receipts to our Japanese insurer to re-claim it (possibly after getting it translated to Japanese, which is generally expensive). I've been told that this generally takes over 4 months, if it happens at all. Also, communication with the insurer is very difficult, as the level of English in Japan is generally abysmal.
This is not ideal.
Therefore, we're looking for a better solution. My wife is "unemployed" (meaning, she does the hardest job of all). Now, if we'd get health insurance from a German insurer, we apparently fall in a category that is not really well defined. In practice this means I pay the amount I would normally pay if I would be working for a German employer, sans any discount. This amounts to about €650.
But in Japan, I already pay roughly €800 for health insurance. This is regardless of whether they are my dependents or not -- this is a fixed amount (see the link above).
We've asked the German insurer if they can act as a proxy; that the German insurer acts as a communication channel between us and the Japanese insurer. According to our previous German insurer (TK), this is not possible.
A dubious solution we've conjured up is that my wife takes a "job" for a friend of ours who has their own business. My wife would get paid a minimal €450.01/month (which goes into our bank account and straight back to our friend). This way, officially speaking, my wife would be "employed", thus reducing our insurance burden to a little over €100.
This is not ideal.
So, in my situation, what is the cheapest way to have everyone insured without breaking/bending the law?
UPDATE: so we spoke with a German insurance agent. He said that German law requires her to be insured, so if she'd have a Japanese insurer, she'd have to go to Frankfurt in person (4h drive with 3 kids) with a bunch of forms to prove that the Japanese health insurance covers the same things as a German insurer would. There are no insurers that will act like a proxy (so it's not limited to TK), and on top of all that, individual hospitals and doctors have the right to refuse the Japanese insurance.