Chie Shimpo, 48, will next month become president of Nomura Trust and Banking, as Japanese Prime Minister Shinzo Abe calls for more women to join the labour force and for companies to bring female employees into the boardroom.
None of the nation's three biggest banks -- Mitsubishi UFJ, Sumitomo Mitsui and Mizuho Financial -- have top female executives, according to a government survey.
The central bank, Bank of Japan, has just one woman on its nine-member board.
Nomura yesterday announced the appointment of Shimpo, who last year told an online Japanese business magazine that her gender was not a factor at the office.
"When I'm at work, I don't really think about my gender," she was quoted as saying.
"I've never thought I was disadvantaged professionally because I'm a woman... (but) maybe it's more correct to say I assimilated" into a male-dominated workplace.
She added that "from the viewpoint of my junior female colleagues... I might not have been a role model".
"But I think we need to make a business environment that is comfortable for younger female workers," Shimpo said.
Shimpo, who has an MBA from Stanford University and also graduated from Japan's prestigious Waseda University, joined Nomura in 1989. She became an executive officer in 2012 after working in the share trading and bond department.
Japanese women are under-represented in business and politics compared to other developed nations. But Abe has pledged to shake up workplace demographics as part of his broader bid to revive the world's third-largest economy.
Most Japanese working women quit after having their first child, according to government data, since long hours and few childcare options often make re-entry into the labour force difficult.
This week Keiko Tashiro became a director of Daiwa Securities, marking the company's first internal appointment of a woman to its board.
Last year Canadian Sarah Casanova made headlines when she was chosen to head McDonald's Japan, joining a small group of foreign-born executives to lead major Japanese firms.