You will be able to bring your medicines up to 1 month's supply without "Yunyu Kakunin-sho".
If you bring medicines for more than 1 month's supply, you need to apply for "Yunyu Kakunin-sho" before leaving your home country.
Please make sure to bring your prescription when entering Japan.
Once you arrive in Japan, apply for "Yunyu Kakunin-sho" before your medicine runs out within a month.
Once "Yunyu Kakunin-sho" is approved, you will be able to ship the medicines to Japan from your home country.
You can get some of the medicines prescribed in the medical institutions in Japan based on the current prescription from your home country, but there is a possibility that you cannot get the same or equivalent medicines.
Please find the details for bringing medicines into Japan from the following URL.
If you have any questions regarding bringing medicines into Japan, please contact the Ministry of Health, Labour and Welfare of Japan.
https://www.mhlw.go.jp/english/policy/health-medical/pharmaceuticals/01.html
https://www.mhlw.go.jp/english/policy/health-medical/pharmaceuticals/dl/qa2.pdf