Mitsubishi UFJ Financial Group Inc., the lender that has made about $13 billion in acquisitions overseas since its founding a decade ago, is making a pivot toward its home market.

"A financial institution's mother market should be its first priority," Nobuyuki Hirano, president and chief executive officer of Japan's largest bank, said in an interview. "We're seeing clear signs that capital investment is gaining traction."

Hirano's optimism that Prime Minister Shinzo Abe will be able to reignite the economy after a second-quarter slump contrasts with Nobel laureate Paul Krugman, who said that he's "really worried" about Japan's prospects. Mitsubishi UFJ has sought to protect itself from a sluggish domestic market with acquisitions from the U.S. to Thailand that have helped more than double its overseas loan balance over the past five years.