Google Person Finder can be used to look for someone in Japan. It is a special social network application that was developed by Google.
Google first developed the application for finding missing people in the Haiti earthquake disaster. But, it extended this to Japan following the country's 2011 earthquake. The application is available in Chinese, English and Japanese.
Instagram, which is an online social networking, video and mobile sharing site, can also be used to look for someone in Japan. This is done by entering a person's username or name into the search box. The search results will be dependent on various factors that are related to the searcher's Instagram usage.