Women have gained more responsibility -- along with tasks -- in the workplace, but now are also expected to devote more time to housework, according to a 1998 white paper on gender equality submitted to the Cabinet Friday.

Single working women usually spend less than an hour on housework each day, but the time increases to more than four hours once they get married, or even up to seven hours if they are unemployed, the report says. Men on the other hand spend only about 20 minutes on household chores, regardless of their marital status.

"The fixed stereotype of gender roles forces women to make a major change in their lifestyle after marriage, which is causing women to get married later," said Haniwa Natori, director of the Office of Gender Equality. "This (stereotype) is a challenge for our society in general."