To import medicines from overseas is subject to control by the Pharmaceutical Affairs Law and the Customs Law to prevent health hazard caused by defective products.
Therefore, when you enter into Japan, procedures should be done depending on your bringing medicines even if you have medicines for personal use.
1. Drugs, Quasi drugs
You can bring your personal medicines into Japan once certain procedures are completed. This is because there are patients who need continuous medication and travelers who need medicines as belongings, however, when you bring narcotics and psychotropic described in 4, please note that importing them from overseas is subject to control by other laws and rules.
To be more specific, when you bring your personal medicines into Japan, you have to apply for so called "Yakkan Shoumei", a kind of import certificate, and receive it before you leave home, and declare it to the officer at customs.
When you bring your personal medicines into Japan up to the amount described below, you do not have to apply for "Yakkan Shoumei", instead the officers at customs check the amount of your bringing medicines, and then you can bring them into Japan.
◆ Poison, Deadly poison, Prescription drug : Up to 1 month supply
◆ Drug for external use (excluding Poison, Deadly poison, Prescription drug) : Up to 24 per one item
◆ Injectable drug and Syringe for the drug: Up to 1 month supply
* Only "Pre-filled Syringe" or "Self-injection Kit"
◆ Other Drugs, Quasi drugs : Up to 2 month supply
Regardless of the description above, you cannot bring prohibited drugs and controlled drugs into Japan.
Regarding details about application for "Yakkan Shoumei", please check "Q&A for those who are bringing medicines into Japan", which includes application forms.
For more details please visit the government site