[Sangetsu]

Opening a business in Japan is not much different than in other places, though being a foreigner complicates things, and makes getting started up more difficult.

The first thing you will need is money. A business license and the legal fees of setting up a basic corporation will be around 300,000 yen ($3000). You will also need a physical address for your business, so you have to add the cost of renting a building and the associated expenses. You will also need to sponsor yourself for a business/investor visa, which usually requires that you have 5 million yen in savings. The initial 300,000 yen will cover the license, application
fees, business stamp, and setting up a bank account in Japan.

Provided you have the money, you can usually get yourself set up in 30 to 60 days, at least as far as paperwork goes. You'll probably need to spend some time and money getting your building/office/store set up, but most Japanese contractors can get the work done in a week.