This article was published in the International Journal of Scientific & Technology Research (IJSTR) [© 2015 International Journal of Scientific & Technology Research (IJSTR) ] and the definite version is available at: http://www.ijstr.org/Japan is the world‘s third largest economy. But currently economic situations of Japan are not stable. It is not increasing as expected. Since 2013 it was world second largest economy but Japan loosed its placed to China in 2014 due to slow growth of important economic indicators. By using the basic Keynesian model, we will provide a detailed analysis of the short and long run impacts of the changes for Japan‘s real GDP, rate of unemployment and inflation rate. We demonstrated a detailed use of the 45-d...