By Jonathan Head in Tokyo

Just days after breaking down the walls of one exclusively male club, Japan's first woman governor has set her sights on another.

Fusae Ota, who was elected governor of the city of Osaka on Sunday, has thrown down a challenge to the traditionally male world of sumo wrestling.

Mrs Ota has said she wants to follow the example of previous governors and present an award at the sumo wrestling championships next month.

But the local Wrestling Association has rejected her request on the grounds that women are not allowed to step inside the ring.

For the past 50 years, it has been a tradition that the governor of Osaka presents an award to the reigning sumo wrestling champion.

It is a custom that Mrs Ota wants to continue.

But that would require her to step inside the clay circle where wrestling matches take place, which is regarded by sumo wrestlers as sacred and out of bounds to women.

Equality superseding tradition

Ten years ago, another woman politician, Cabinet Secretary Mayumi Moriyama, tried the same thing. She was forced to back down.

But Governor Ota believes the tide of history in Japan is now running in her favour.

After all, her election victory followed the forced resignation of the previous governor of Osaka over allegations of sexual harassment, an issue that used to be largely ignored in Japan.

And other traditionally all male preserves are beginning to crumble.

Japan's national railway has just started training the first female drivers for the super fast Bullet Train.

Osaka Sumo Wrestling Association says it is just trying to protect its traditional culture by excluding women.

But it may find it difficult to resist the growing drive in Japan for sexual equality.