I plan on taking photos of everywhere I go in Japan and am wondering if there are certain places, e.g. airports or possibly temples, where photos are not to be taken.
A link to online resources would also be welcome.
Japan, birthplace of the camera phone, is relatively photo-friendly if you are taking candid pictures for your personal use with your own camera (i.e. not for publication or resale and not using a tripod or professional equipment). Places where photography is expressly forbidden will be marked by signs. By and large, these are the same places where you can expect photography restrictions in any part of the world: some religious sites, some museum exhibits, some stores or businesses, security checkpoints, or military facilities. Other places may have restrictions on flashes, or simple common sense should tell you not to use a flash, such as train platforms, construction sites, or love hotels.
But these days, my sister tells me, there are a lot more signs. Even some street displays and storefronts have prominent "no photography" signs posted. Perhaps this is a backlash to the ubiquitous cameras, and problems like like people taking pictures of manga or magazine pages instead of buying them, or clandestine shots being posted to voyeur websites. So, it will be important to communicate intent. Department stores and boutiques are very sensitive about people taking pictures of their trendy displays and products, though you will find people taking pictures of products to research later. Similarly, people are sensitive to having their faces plastered all over Flickr without their knowledge, regardless of intent. But if you approach an individual and ask to have your picture taken with him or her, he or she may well say yes in order to indulge a foreign visitor.
I'm not aware of any canonical resource on photography restrictions, aside from a very very dated photo.net guide (the comments are more enlightening than the article).
Somewhat more recent discussions include