When Chiho Higo started teaching stock trading at a Tokyo night school in 2008, there were often no female attendees. Now there are 50. One mother said she bought shares in a toymaker instead of toys for her child.

"If there was a woman, she usually looked like she'd wound up there by accident," Higo, a 36-year-old lecturer, said in an interview in her classroom at Tokyo's Financial Academy. "Now in some lessons, it's like a girls' night out."

That's welcome news to Japanese institutions that have struggled to entice women to invest in stocks, no easy task in a market that has returned 1 percent a year for three decades.