Despite an economic depression which goes back to the early 1990s, Japan enjoys an enormous consumer goods and services marketplace. This includes a love for foreign goods and a desire to travel abroad.
When I was in Japan this summer, I lived with a host family and watched a fair amount of broadcast television. There were many shows dedicated to foreign culture and sightseeing. Places within Asia (Singapore, China, Thailand, Indonesia, Guam, the Philippines) are popular due to their proximity to Japan, and because many tourist areas have Japanese-speaking staff. For similar reasons, Hawaii is popular: furthermore, there is a large Japanese immigrant population and a lot of beautiful island scenery. Outside the Far East, popular destinations include Western Europe and North America. Because Japanese is not widely spoken in Western tourist areas, English sometimes becomes the language for conversation with varying degrees of efficiency.
Rather than put up with a language barrier, Japanese tourists sometimes travel in large groups. Of course, many other countries organize these groups as well, but the urban Japanese love affair with all things foreign has encouraged a large travel industry. Despite security fears and stagnant economic conditions, travelers are still heading to the U.S. This is not meant to discount the effect of terrorism on air travel, as Japanese visitors to Hawaii have dropped by about 20% since 20011 for example.
To many locals, Japanese tourists are an amusing sight: by forming into large groups and speaking only to those in their "in-group," Japanese manage to stay within their comfort zone of language and culture no matter where they go. Many Japanese feel the same way about groups of Americans and Europeans who visit Japan, particularly in areas like Tokyo that receive a lot of foreign visitors.
Stereotypes about Japanese tourists are that they wear garish, brightly colored clothing and are never seen without a camera around their neck. The same stereotypes exist for American tourists, and both Americans and Japanese are known for looking out of place due to an unwillingness to assimilate during such a brief visit to foreign cultures. As long as everyone's having fun and staying safe, travel on.