A man walks past a Nomura Securities branch in Tokyo
If a downgrade happens, Japan’s biggest brokerage, Nomura, will hold a "near-junk" rating. Reuters

Nomura Holdings (NYSE: NMR), Japan's number one securities firm, has appointed a woman to be its chief financial officer for the first time ever.

Junko Nakagawa, 45, will begin her new role on April 1, Nomura said.

It is an unusual move since traditionally men have dominated senior business executive positions in Japan.

"We have not named Ms Nakagawa as CFO because she is a woman but because she has the capacity to do this job and assume the responsibilities," a Nomura spokeswoman told Agence France Presse. "That said, we think it is good to encourage diversity in our business.”

Nakagawa has held a number of senior positions within Nomura since joining the firm in 1988. She also led several key projects, including Nomura's listing on the New York Stock Exchange in 2001.

"It is rare for a Japanese financial institution to give this type of promotion to a woman," said Azuma Ohno, a brokerage analyst at Credit Suisse Securities in Tokyo, according to BBC. "It's an impressive move."

Moreover, Nomura has also appointed Indian-born Jasjit "Jesse" Bhattal as group deputy president and chief executive of the wholesale banking division, making him the highest ranking foreigner in any Japanese firm.

Last year Bhattal became president and chief operational officer of Nomura's global wholesale banking division, making him the first foreigner to join the firm's executive committee.

Nomura is trying to make itself more of a global player to compete with Goldman Sachs, among other giants, and obviously seeking to adopt management styles of foreign companies,

Nomura acquired the non-US assets of Lehman Brother following that company’s collapse in 2008.

Takumi Shibata remains as chairman of the wholesale business as well as chief operating officer of Nomura Holdings.

Masafumi Nakada, the current chief financial officer, will become president of Nomura Trust & Banking Co.