The strengthening yen may have sent Japanese shares into a swoon, but it isn't clear how much companies need to worry about whether a stronger currency will take a bite out of profits.
The yen has strengthened around 4 percent against the U.S. dollar so far this year, potentially frustrating expectations the Japanese currency might weaken substantially further.
(Read more: How bad will the Nikkei meltdown get?)
So far, earnings reports for the just completed quarter appear to be mostly in line with or above expectations, but as the yen strengthens, some are concerned about whether the strong performance can continue.
"Company by company by company, it really is spectacular. You find that almost one in two companies in the current reporting season exceeds the analyst expectations," Jesper Koll, head of Japan equity research at JPMorgan Securities Japan, told CNBC.