TOKYO, Oct 13 (Reuters) - Japanese stocks fell on Thursday as cautious traders braced for a key U.S. inflation reading that could influence global central banks' aggressive narrative on interest rate hikes.

Japan's Nikkei share average started the session higher, but shed early gains to close 0.6% lower at 26,237.85.

The broader Topix fell 0.77%.

"Overall there's a feeling of slight position adjustment," said Mitsushige Akino, chief fund manager at Ichiyoshi Asset Management.

The immediate focus for investors now is U.S. consumer price data due later in the global day.

"We want to see how the market reacts. The CPI has been making big movements each month of late, and this time it could fluctuate significantly either upwards or downwards, so we expect investors will want to reduce positions in advance," Akino said.

Federal Reserve Governor Michelle Bowman struck a hawkish stance in a speech on Wednesday, saying that if high inflation does not start to wane she will continue to support aggressive rate hikes.

Last month, CPI data showed that U.S. inflation accelerated more than was broadly expected, sending Wall Street to its biggest daily loss in more than two years with the Nikkei tumbling in turn.

Toshiba Corp was the most notable mover on Thursday, jumping as much as 9.41% on a report that a consortium led by Japan Industrial Partners is looking to buy the conglomerate for 2.8 trillion yen ($19.07 billion).

Toshiba shares closed 7.38% higher, marking Thursday's biggest impact on the Topix index.

Semiconductor stocks rebounded after a rocky few sessions. Chipmaking equipment manufacturers Tokyo Electron Ltd and Screen Holdings Co Ltd both gained nearly 2%.

Sony Group Corp fell 0.46% while Honda Motor rose 0.97% after the two companies announced its new joint venture, Sony Honda Mobility, would sell a premium-priced car online in Japan and the United States by 2026.

Movie producer and cinema operator Toho Co Ltd made the biggest loss on the Nikkei, down 3.84% despite announcing an upwards earnings revision and a 6 billion yen ($40.86 million) share buyback.

Of the Nikkei's 225 constituents, 164 declined, 58 advanced, and three traded flat. (Reporting by Sam Byford; Editing by Sherry Jacob-Phillips)