There are different Business Directories :

Try all different Business Directories offered by
Every Engine has different results,
Most companies are listed in serveral directories
but the results are not the same ...

find products
and order them directly (example Sony Cameras, Pokemon, Video Games)

Products via Amazon

Business to Consumers
Companies froviding Products or Sevices for End Users
(example Restaurant)
B2C Town Pages by NTT (Japanese only)

B2C Directory NTT-JP

Business to Business
Companies providing Products for Professionals
(example Manufacturer of Kitchens)

Gov Search
Government of Japan
search through the government
Japan Gov Search
this search engine goes through
all the Japanese ministeries,
maybe the company you are looking for
has been mentioned.

search in another country
Phone Book of the World.comPhone Book of the
Annuaire du
maybe the person you are looking for has moved
and can be cound through the directory of another country

good luck ...