Perth

Japanese citizens require either a visa or ETA registration through the Australian ETA app to enter Australia.
ETA app:

Your passport must be valid for at least the number of days of your stay.

The $60 departure tax for flying out of Australia (PMC) (Scheduled to be $70 from July 2024) and various airport taxes for each airport are generally paid at the time of purchasing your flight ticket.

When visiting from Japan, it is prohibited to bring the following items into Australia.
Australia is far from the other continents and has many unique species of plants and animals. For this reason, quarantine is extremely strict and there are very detailed regulations for bringing in foods, plants, and animals. The following is a list of typical items that are not permitted to bring into the country for details, see Australian Quarantine and Inspection Service website (https://japan.embassy.gov.au/tkyojapanese/quarantine_jp.html).
Some items may be brought in if declared.

Visitors will not be taxed for bringing in commodities for non-commercial use carried on hand or in hand luggage, sports goods for personal use, up to 25 grams of tobacco and one opened box (over 18 years old adults only), up to 2.25 liters of alcohol (adults only), or $900 worth of general goods (e.g. gifts, leather products, electronic devices, cameras, or jewelry).

E-cigarettes are not the norm in Australia and are considered pharmaceutical products that require a doctor’s prescription to buy there. Although there is no explicit law prohibiting visitors from bringing it them in, they must be included in your customs declaration when entering the country as they are considered pharmaceutical products (the amount allowed and other factors are determined in the customs inspection based on the length of stay). It is also very likely that the laws for e-cigarettes will become more strict, and it is best not to bring them to avoid unnecessary trouble.

Australia generally has three time zones. The time difference is +1 hour between the states on the east coast (add 1 hour to Japan time). Central Australia has a -30 min. time difference with the east (add 30 min. to Japan time). The west (Western Australia) has a -2 hour time difference with the east (subtract 1 hour from Japan time). In addition, Daylight Saving time is in effect generally from the first Sunday of October to the first Sunday of April in New South Wales, Victoria, the Australian Capital Territory (Canberra), Tasmania, and South Australia. Add an extra hour to the time for these states and territories during this period. Note that the adoption and period of Daylight Savings time is determined by each state/territory each year, and you should check in advance the terms for that year.

Australia is very large and has a range of climates. In general, the north coast is a tropical zone and is divided into a rainy season and a dry season, central and south coast is a temperate to cold temperate zone with four season, and the central part of the continent has a dry desert climate. The sun is very strong throughout the year, so sunglasses and sunscreen are essential.