In case you are thinking of investing on and setting up a company to operate your own business in Japan,you are mostly required to obtain this " Investor/Business Manager"visa.Or when you are going to operate or manage international trade or other business on behalf of other foreign investors (including foreign companies)which have already started such business in Japan,it is also necessary for you to apply for it. "Business Manager"means here a person actually committing the company administration and management,e.g.CEO,president,vice
president,director,manager and branch representative etc.
However,if you already have those types of visa which allow you to engage in any activities without restriction,such as Permanent residency, Spouse of Japanese National or Permanent Residency etc., you don't need to apply for this kind of visa.