I live in Chile and experienced the massive comms breakdown after the earthquake. Best advice is NOT to use telephone at all, you are just making it harder for everyone, including emergency services. Best way to get information is using http://japan.person-finder.appspot.com/?lang=en, email, sms, facebook and other types of asynchronous communication. Be sure to post contact info of people you are searching for on a place they or their friends can see. Rest assured that odds are they are OK, but just incommunicated. Also sending emails to Police/Firefighter stations in Tochigi with info about the people you look for is a good idea. Just once though. My thoughts go with you and your familiy.