Japan Travel Health Advice
No vaccination certificates are required for entry to Japan. Long-term travellers, staying for more than a month in rural areas, should consider getting a Japanese encephalitis vaccination if they are travelling between the months of June and September.
Medical facilities are very good in Japan, but medical assistance can be very expensive and visitors have to pay the whole cost upfront. Travellers should ensure that they have adequate medical insurance before travelling.
Vicks inhalers and other common medications used for allergies and sinus problems are banned under the strictly enforced anti-stimulant drugs law, and visitors are advised to check with the Japanese embassy if in doubt.
It is always best to take prescribed medications with you when you travel, in the original packaging and with a signed and dated letter from your doctor detailing what the medication is and why you need it.