Japan's core consumer prices fell 0.1 percent in August from a year earlier, government data showed on Friday. It was the first year-on-year drop since August 2013.
The core consumer price index, which includes oil products but excludes fresh food prices, matched economists' median estimate for a 0.1 percent annual gain.
The so-called core-core inflation index, which excludes food and energy prices and is similar to the core index used in the United States, rose 0.8 percent in the year to August.
Core consumer prices in Tokyo, available a month before the nationwide data, fell 0.2 percent in September from a year earlier, versus a 0.2 percent annual fall seen by analysts in a Reuters poll.