(Updates with closing prices)

By Kevin Buckland

TOKYO, Aug 28 (Reuters) - Japan's Nikkei share average

closed higher on Wednesday amid a weaker yen, but earnings from

AI darling Nvidia ( NVDA ) later in the day kept investors cautious.

The Nikkei ended up 0.22% at 38,371.76, reversing

early declines, as the yen extended its slide against the dollar

over the course of the session.

That put the index close to the top of its narrow range

since mid-month, which has been anchored around the

psychological 38,000 mark.

The broader Topix slipped 0.08%.

Market expectations for Nvidia's ( NVDA ) financial report

are sky-high, and anything short of a stellar forecast from the

chipmaker could jolt investor confidence in the AI-fuelled

rally.

"The bar is extremely high, and depending on the result,

stocks could swing wildly", which kept Japanese investors

largely sidelined, said Masahiro Ichikawa, chief market

strategist at Sumitomo Mitsui DS Asset Management.

Semiconductor-sector shares were mixed, with chip-testing

equipment maker and Nvidia ( NVDA ) supplier Advantest ( ADTTF ) rising

4.18% to be the Nikkei's biggest gainer by index points. Peer

Lasertec ( LSRCF ) climbed 4.19%.

At the same time, chip-testing machinery giant Tokyo

Electron ( TOELF ) finished slightly lower, while AI-focused

startup investor SoftBank Group ( SFTBF ) slumped 2.29%.

The yen traded about 0.4% weaker at 144.47 per dollar

as of 0611 GMT, reversing course after starting the

day by extending overnight gains to 143.69. On Aug. 15, it

traded closer to 150 per dollar.

A stronger yen reduces the value of overseas sales, while

also making stocks more expensive for overseas investors.

"Even though the yen is weakening a little now, the trend is

for gradual yen appreciation, which is a weight on stocks,"

Ichikawa said.

Automaker shares were mixed, with Toyota Motor ( TM )

rallying 3.88% and Honda ( HMC ) advancing 0.7%, while Nissan ( NSANF )

slid 0.65% and Mazda ( MZDAF ) eased 0.16%.

Rakuten Group ( RKUNF ) led gainers on the Nikkei, jumping

9.19%, following share price target upgrades by Morgan Stanley

MUFG Securities and Citi.