EJ, there are no warnings or restrictions for Japan south of Tokyo. Osaka and Kyoto are on a different power grid so there's no interruption to electricity. Jesse from the safety team here was in Osaka when the quake struck and didn't even feel it.
I'm sure the Japanese people will be happy to have you come and contribute to their economy.
Just don't forget, all of Japan is on the "ring of fire" and earthquakes are unpredictable, so there's no guarantee something else won't happen, so you need to take all the usual precautions (and first of all you should register your travel with your government's foreign office).
Don't worry too much and have a great trip.
Phil about 9 years ago
South of Tokyo is completely safe (unless the unexpected happens - and hey we can easily get hit by a bus too). I live in Yokohama and there is a small risk of radiation poisoning here for young children, but in osaka or areas further southwest are completely safe. about 9 years ago