When bringing a pet to Japan, it is best to start preparing as early as possible in advance of your move. Forms need to be filled out and vaccinations carried out. The whole procedure of importing a pet into Japan can take up to seven months. If you own a pet such as a cat or dog, you need to register it at the local municipal office and also have it vaccinated as soon as possible.
When moving out of Japan, there are also a number of conditions which must be met in advance (a number of weeks before your departure date). You should also contact the Irish Embassy for information and the Japanese Animal Quarantine Service – http://www.maff.go.jp/aqs/english/index.html