The yen’s downtrend has reversed in recent days, following the Bank of Japan’s July 31 decision to raise interest rates and ahead of an expected loosening of U.S. monetary policy.

Yen ETFs track the performance of Japan's currency relative to a single currency (like the U.S. dollar or euro) or against a basket of currencies. Like other currency ETFs, these investments give ...

That gap also makes owning the yen, whose bonds pay 0.5% on average, using U.S. dollars that cost upwards of 4%, an expensive proposition for investors. If the yen depreciates, it's a double-whammy.

Tely's is only 20 minutes from Yen Yen, so he feels certain he'll have no problem running both. "I don't want to abandon Yen Yen," he said. The two restaurants will remain a family affair.