When salaryman Takayuki Nakamura bought his Tokyo home last year, he got a floating-rate mortgage at a rock-bottom 0.35% and an assurance from the real estate agent that rates weren't going anywhere. After this week, he's not sure.

"On Tuesday, all of a sudden I'm hearing the interest rates are going up," said the 48-year-old father of two. "It's kind of obvious that I'm going to end up paying more."

The Bank of Japan whipsawed global financial markets when it said on Tuesday it would allow rates to rise a little more, signaling a potential end to ultralow rates and easy money after decades of trying to revive the world's No. 3 economy.