Japanese business executives, even those who have benefited from a weak yen, are calling for a stronger currency, with Kawasaki saying it would move manufacturing back to its home country if the yen strengthens.

When the yen fluctuates, "we cannot make [a] strategy," Yoshinori Kanehana, chairman of Kawasaki Heavy Industries, told CNBC on the sidelines of the Gastech conference on Tuesday. He said it was the "biggest problem" for the company.

Kanehana said that yen at 150 could make him consider moving manufacturing from the U.S. to Japan. It has 27 production sites outside the country, including in the U.S., and 17 at home, according to a company report published last year.

Takayuki Ueda, president and CEO of energy major Inpex, wants the currency to be even stronger, saying that yen at 100 would be the "appropriate" level, suitable for the Japanese economy.

His comments come even as nearly 90% of the Japanese oil company's business is outside Japan, and conducted via the greenback. That means the business benefits from converting its dollar-based profits into the local currency.

Inpex's revenue fell in the first six months of the year from a year ago as crude oil sales volume dropped, but the company said in its earnings report that a 6.7% depreciation of the yen to 158.37 per dollar helped offset some of that the decline.

"But if we look at the Japanese economy as a whole, the current exchange rate is perhaps too weak," Ueda told CNBC on the sidelines of the Gastech conference in Bangkok on Monday.

While the Japanese yen has strengthened rapidly over the past two weeks, it remains weak in historical terms, with its 10-year rate averaging at about 123 against the dollar, based on Macrotrends data. The yen was trading at 156.3 on Thursday.

Takeshi Hashimoto, chairman of the world's largest tanker owner and operator Mitsui O.S.K. Lines, told CNBC last week that he wants to see a stable currency market, and that he'd be "comfortable" with the yen at 150-155.

Mitsui generates revenue mainly in dollars, benefiting from a weak yen. But "we had some concern that the [weak yen] would create a confused situation in the financial market," Hashimoto said.

Japanese businesses factored in an average exchange rate of 152.51 for the second half of the year, according to a BOJ quarterly survey of business sentiment released in July.

Investors expect the Bank of Japan to hike rates by 25 basis points to 1.25% at its two-day policy meeting that concludes on Friday.

"The stakes are extremely high" for the BOJ, Matthew Ryan, head of market strategy at Ebury, said in a note Monday. He said he expects the BOJ to raise rates and deliver hawkish rhetoric that "effectively endorses a quarterly pace of rate increases thereafter."