Japan, like the rest of the world, uses the metric system.
For time conversion, use this: http://www.timezoneconverter.com/
For currency conversion, use this: http://www.xe.com/ucc/
100 Japanese yen is about a buck. So, 1000円 is about $10, etc. The international symbol for the yen is (¥), and the symbol precedes the number. The kanji for yen is（円）, and it is pronounced without the 'y' (en in romanji). In Japanese, the number precedes the kanji. I'll probably only be posting prices of stuff in yen, so just subtract two zeros from everything to estimate its cost in USD.