The power supply is difficult in Japan and expensive. 100v doesn't work but fortunately my air conditioner is 220v, so I use that plug to run the miner during the winter rather than the air conditioner or gas stove. It subsidies the heating bill and allows me to grow my bitcoin stack.

Nerdminer is good for just understanding the process but the Antminer s9 (can buy on ebay for under ¥30000) is really the first step into mining.