Come April, when Japan's sales tax rises to 8 percent from 5 percent, a large cup of Starbucks green tea in could jump to 572 yen from 550 yen. The price will fall to 530 yen with the sales tax completely excluded. And of course, retailers can choose to absorb none, some or all of the tax.
In the same vein, the Nikkei chart has well-defined upper limits and downside targets.
(Read more: Is the BOJ at its limits?)
The chart is dominated by two features. The first feature is the uptrend line that defined the rising trend which started in April 2013. This trend line acted as a support level until January 2014. The fall below the trend line signaled a change in the nature of the uptrend. After January 2014 the uptrend line acted as a resistance level. This caps any future index rises with the current upside target near 15500.