[lmm]

> Does Japan National Tax Agency also let you see other details - like parent company of the entity, or any other information?

Not from the tax agency. For a KK you can get a list of investors from the legal affairs bureau for a small charge, and for any kind of company you can get a history of who has ever been representative director or equivalent. AIUI it's possible to have a "silent partner" setup where you have a partnership or GK and the representative is a lawyer rather than the person actually operating and profiting from the company, but there always has to be at least one publicly named representative.