When a 210-year-old vinegar company bought Unilever's Ragu and Bertolli pasta sauce business last month, it showed that Japanese firms are becoming more adventurous in their search for growth, said Goldman Sachs Group Inc.'s national head of mergers and acquisitions.

"Japan M&A is breaking boundaries," said Yoshihiko Yano, who is also a participating managing director at the U.S. firm. "We have to be more creative and steer away from biases and assumptions like 'This company will normally do this,' or 'This type of move may happen in this industry.' "

Japanese companies are pursuing mergers at home and abroad to counter a shrinking population, and Yano said they're increasingly taking advantage of low borrowing costs and rebounding share prices to help fund transactions. Takeovers involving the nation's companies were valued at $56.7 billion in the six months ended June 30, up from $49.1 billion a year earlier, data compiled by Bloomberg show.