somehow i agree with bro RegentCid
lots of people tend to ask me about Japan like "apa yg best Jepun, mahal ke sana, senang ke makan", and ask for other advice without doing any homework...
our preferences might be different, something that is enjoyable to me, might be very boring to others...
so do your research, find which attractions you wanna go, how to go there, how much needed to go there.
Japan-Guide, Hyperdia, Wikitravel, Google Maps and other travel blogs will give you the answer.
Plus, learn also about the country, the language, the culture...
once you do that and then go see the real thing... the feeling is so AWESOME
and for the radioactive thingy, i believed Japan is the most strict country in term of safety, if you wanna compare the level of pollution in Malaysia and Japan... i prefer to live in Japan
Just my two cents