Hokkaido is an island in the northernmost of Japan. Throughout the year, Hokkaido is relatively cool and has low humidity. July is one of the best times to visit Hokkaido.
Average temperatures in the summer range from 20 - 25°C which means that the climate is very comfortable when compared to the extreme humidity of Japan's main island. In this way, Hokkaido in the summer is perfect for such activities as afternoon strolls or driving down the road in a rental car with the window open as you enjoy the fresh breeze.
Clothing: Day time temperatures provide the perfect conditions for walking around in short sleeves and half pants but in the evening it is advisable to wear a parker or light top as the temperature can drop somewhat. In the evening before retiring to bed, long sleeved pajamas and bottoms are recommended as the evening and mornings can be a little chilly.

In Japan, 2-flat-pin plugs are used instead of columnar-shaped plugs or 3-pin plugs. The voltage used throughout Japan is uniformly 100 volts, A.C. There are two kinds of frequencies in use; 60 Hertz in western Japan and 50 Hertz in eastern Japan (including Hokkaido). A convertible type of electrical appliances such as a travel iron, hair dryer, and shaver will therefore be handy. Otherwise, a step-down transformer is required to convert the voltage. 2-PIN 2-PIN + EARTH

The local currency is Japanese Yen (JPY). Japanese money comes in bills (1,000, 2,000, 5,000 and 10,000 yen) and coins (1, 5, 10, 50, 100 and 500 yen). Major currencies, such as the US dollar and EURO, can be exchanged at international airports, major banks and major hotels. Banks are open from 9:00 to 15:00 on Monday to Friday.

Traveler's checks are accepted by leading banks and hotels in major cities. International credit cards such as American Express, VISA, Diners Club, MasterCard and JCB are also acceptable at these major establishments. Credit card transactions, however, are not always convenient outside big cities. Therefore, obtaining cash beforehand is recommended when you travel to the countryside.

Personal effects and unaccompanied baggage that are for personal use, are free of duties and/or taxes within the allowance specified below. If you have both personal effects and unaccompanied baggage, please consider them together when referring to the allowance.
Clothes, toiletry articles, and other personal effects that are for personal use, as well as professional equipment that will be used during your stay in Japan, are all free of duties and/or taxes, if they are considered quantitatively appropriate and are not for sale.
More Information for the "Customs Declaration" :
http://www.jnto.go.jp/eng/basic-info/shopping/customs.html

Tipping is not necessary unless you request some extra special service. Individual tipping is not common in Japan, since a 10 to 15 % service charge is added to the bill at major hotels and higher-class restaurants.

Japan is in a single time zone, nine hours ahead of GMT. No Daylight Saving Time is in effect.

The organizers do not accept responsibility for individual medical, travel or personal insurance. Participants are advised to take out their own personal insurance policy.

Japan has visa exemption agreements with 61 countries and regions (as of April, 2012). Citizens of these countries who plan to stay in Japan no longer than the period specified in these agreements do not require a visa. Foreign participants should contact the Consular Section of the Embassy or Consulate General of Japan nearest you as soon as possible, to determine their particular visa requirements. Those requiring visas must initiate the application process well in advance of their departure date.
More detailed information how to obtain a Japanese visa is shown at the website below.
"Ministry of Foreign Affairs of Japan" http://www.mofa.go.jp/j_info/visit/visa/