(Updates with closing levels, adds RSI levels in 7th, Toto

shares in 10th.)

By Rocky Swift

TOKYO, June 22 (Reuters) - Japan's Nikkei share gauge surged

past the 72,000 mark for the first time on Monday, on continued

euphoria over AI investment and some progress in the U.S.-Iran

peace talks.

A joint statement by Qatar and Pakistan, mediators in the

negotiations, said the U.S. and Iran agreed to a roadmap toward

a final deal within 60 days.

The benchmark Nikkei 225 advanced 1.55% to close at

72,353.96, after touching an intraday record peak of 72,831.73.

The broader Topix gained 1.24% to 4,095.05.

Japanese Prime Minister Sanae Takaichi's administration

plans to set a target of about 370 trillion yen ($2.29 trillion)

in public and private investment in strategic sectors including

AI and chips by 2040, the Nikkei reported on Friday.

"AI-related companies are once again playing a leading role

in driving the market," said Wataru Akiyama, an equities

strategist at Nomura Securities.

There are signs the Nikkei is "overheating," Akiyama

cautioned.

The gauge climbed for an eighth-straight session, its

longest winning streak in more than three years. A technical

indicator, known as the 14-day relative strength index, for the

Nikkei stood at 73, above the 70-mark indicating that shares may

have risen too fast and are poised for a reversal.

There were 137 advancers in the Nikkei 225 against 85

decliners.

J.Front Retailing was among the leaders, surging

15.9% after activist investor 3D Investment Partners said it

took a 5.10% stake in the department store operator.

Shares in Toto soared 11% to a record after the

Nikkei said on Sunday that the bathroom fixtures maker will

invest 80 billion yen over the next five years in its

semiconductor manufacturing equipment components business.

Taiyo Yuden ( TYOYF ), down 9.14%, and Tokyo Electric Power ( TKECF )

, 7.10% lower, were the largest losers.