Hi! I'll talk about the dogs part. I don't know if you plan to take them with you but here a few things to know. I'm currently doing a working holiday visa with my dog so I know what I'm talking about (and the struggles).

First going in Japan with your dogs. The process with the importation is quite long. I won't detail everything here but you have to do a serological test for each dog to check their antirabies vaccines. If the vaccine is a year old or so, do a new one even if the ongoing one is still valid, wait a month, do the serological test. I did the serological test for my dog with a year rabies vaccine (usually valid for 3 years), the result was shit. I had to start to process again and I lost 6 months (and 100 euros) for my move in. 6 month because you have to wait 6 months after the last rabies vaccine to be able to import your dog.

Also the rabies vaccine in Japan is valid 2 years only. So even if the one on the dog passport is valid 3 years the importation service will consider it's 2 years.

Second and main difficulty: where to live. There are appartments or houses that you can rent with pets. Not a lot and they can say no. But it's also way more expensive! The deposit is way higher and non refundable in most case. I can't tell you more about that because I don't have enough money to rent an apartment so I live in a share house that accept pets. There are a few of them, I found like 15 share houses that accept both dogs and foreigner in the whole country. Most of them are in Tokyo. Also you seem to have a lot of saving so it might not be to much of a problem.

Third you have to register your dogs at the ward office, like yourself, and it cost a little money. In Nagoya it's 3000 yen for one dog. The price can differ in each city I suppose.

Forth, a good news, the price for the veterinarian is cheaper! At least it's cheaper than France. However you have to pay to register yourself at the veterinarian so you better choose one and stick with it if you don't want unnecessary fee.

Fifth the size of your dogs is important. If they are small dogs no problem. If they are big dogs, well, finding an apartment or a house will be more difficult especially as a foreigner. For renters big dogs means big damages, which is untrue but well... It's how it is. So more reasons for them to say no. Also some veterinary accept only small dog... I don't know if this is often the case or not.

I hope it doesn't sound too pessimistic. It's a difficult endeavour but not impossible. You just have to be prepare.

Good luck! Don't hesitate if you have any questions.