On Japan's Pharmaceuticals and Medical Devices Agency (PMDA) website, you can find in the section "Regulations and Procedures" under the heading "GMP" requirements regarding the inspection of manufacturers of medicinal products and APIs who want to introduce their products into Japan.
Now, a document was supplemented in January 2014 which describes which documents have to be submitted to the Japanese Agency within a pre-approval inspection and/ or a periodical post-approval inspection.
Go to the PMDA webpage to get more information.
There, you can also access the current Japanese Pharmacopoeia Sixteenth Edition in English.
Source: PMDA, Japan