Overall nationwide consumer prices in Japan were up 2.5 percent on year in September, the Ministry of Internal Affairs and Communications said on Friday.
That was beneath expectations for 2.7 percent and down from 3.0 percent in August.
On a monthly basis, overall inflation fell 0.3 percent after rising 0.5 percent in the previous month.
National core CPI was up 2.4 percent on year, exceeding expectations for an increase of 2.3 percent but down from 2.8 percent a month earlier. Core CPI was up 0.2 percent on month, easing from 0.5 percent in August.