Japan has not yet introduced any preferential treatment for foreign visitors to get permission to enter with a vaccine passport; therefore, foreign nationals from Germany, for example, will not be allowed to enter unless there is some humanitarian grounds or other reason not involving business purpose. You could start with a certificate of eligibility application first at a local immigration bureau as an entrepreneur via your representative in Japan, or simply wait for the day when the entry ban is lifted and you can visit under a visa exemption program.
