Think about it this way. its 121.34 yen to 1 American Dollar. so 100,000 yen is really $824.13.
So its not enough, not even for the States. Be sure to know the currency exchange for whenever you go to another country.
Use this website to see the change of currency rate and see the value of the Japanese Yen to the American dollar or another country. Its a good way to see how much you'll really knew. But you should always plan to have more then you'll actually need.
Currency Calculator
Also talk to someone who live in Japan and see how much they spend. There is a guy who is engaged to a woman from Japan and she is currently living there. I think he can ask her for you.
http://www.japanforum.com/forum/livi...ing-japan.html
Hope that helps. ^_^