I assume a lot of foreign visitors are expecting to buy home appliances sold in Japan. Then, there are two reasons to buy the products in Japan.
1 - It is cheaper than in the home country.
2 - The model is not sold in the home country.
Home appliance can be cheaper due to the VAT - consumption tax in Japan is just 10%. Then, foreign tourists also can enjoy TAX FREE at certain stores.
Then, some products are not sold in Europe. I assume no one will buy fridge or washing machine sold in Japan but rice cookers and other home appliances which can be brought home.
Some of the home appliances are adapted to use outside of Japan and multi-language manuals are available. However, some products are intend to use solely in Japan and may be you have to buy a transformer or translate the manual.
Anyway, many major stores in big cities now employ employees who can speak either English or Chinese. Especially the stores which offer TAX FREE have bilingual staffs. Do not hesitate to ask them!