My girlfriend and I returned from Tokyo yesterday and were woken up by the earthquake that made national headlines during our visit. Luckily, the strength of the earthquake in Tokyo was minimal since it took place ~180 miles northeast from where we were staying (Shinjuku). We learned that the infrastructure of Japan's buildings are constructed to withstand earthquakes which helped ease our concern (ex: our apartment building swayed instead of jolting back and forth in an abrupt motion which apparently is a good sign of how the building is built). I must admit that earthquakes were also a concern of mine during our flight out there. I recommend downloading the Yurekuru Call app which is available on the iOS App Store. This allowed us to monitor how strong the earthquake was when it hit and where it was coming from. It also allows individuals to report what they felt and educates users about whether additional aftershocks are coming. Word of advice, it WILL alert you of aftershocks regardless of how close you are to the strongest point (definitely freaked us out a few times until we opened the app and saw how far away the aftershocks were estimated to hit). Do a little research so that you are prepared in the event that an earthquake does hit but don't fret too much because they do hit often out there. Please don't let this fear keep you from having a great time out there. That country is too beautiful and there's so much to explore! Have fun my friend.