Disaster in Japan
Usually, people say that Kyushu isn't a region with high disaster risk. However, recently events (Kumamoto earthquake 2016) proved us it is.
When disaster occurs, japanese cell phone will inform you few seconds in advance, so you can try to find the safest place, and wait until it ends.
Many foreigners are not used to earthquake and don't know how to react or how to prepare themselves to it.
You can find a PDF from the FIEF (Fukuoka International Exchange Foundation) that explains what you should do in the case of different disaster.