The third time inflation has fallen to zero in this year persuaded some market watchers that "Abenomics" needs to be taken back for an overhaul.
The government will be forced to delay an increase in the sales tax scheduled for April 2017 and the Bank of Japan will be unable to taper its unprecedented bond buying as envisaged, according to Sumitomo Mitsui Banking Corp.
Only one economist in a survey by Bloomberg from July 27 to Aug. 3 said inflation would reach the BOJ's goal in its target six-month period through September 2016. A majority of the 37 respondents see the BOJ boosting monetary stimulus.