The following countries can gain entry to Japan without a visa. Length of stay varies from 30 to 90 days depending on your nationality.
Andorra, Argentina, Australia, Austria, Bahamas, Barbados, Belgium, Brunei, Bulgaria, Canada, Chile, Costa Rica, Croatia, Cyprus, Czech Rep., Denmark, Dominican Rep., El Salvador, Estonia, Finland, France, Germany, Greece, Guatemala, Honduras, Hong Kong, Hungary, Iceland, Ireland, Israel, Italy, Latvia, Lesotho, Liechtenstein, Lithuania, Luxembourg, Macau, Macedonia, Malaysia, Malta, Mauritius, Mexico, Monaco, Netherlands, New Zealand, Norway, Poland, Portugal, Republic of Korea, Romania, San Marino, Singapore, Slovakia, Slovenia, South Korea, Spain, Suriname, Sweden, Switzerland, Taiwan, Thailand, Tunisia, Turkey, U.S.A, United Kingdom and Uruguay
All foreigners should expect to be photographed, fingerprinted and questioned each and every time they enter Japan.
Japanese visa exemption rules
Foreign embassies in Japan