The minimum wage system was introduced to the Korean labour market in 1988 as a buffer against income gaps. However it has not performed well as a buffer since the legal amount is set too low. Furthermore, it often served employers' interest to fix low wages. Its negative impact became even more obvious when the IMF crisis hit South Korea in 1997 and led to a rapid increase in the number of sub-contracted workers. 

In 2001, the KWWAU conducted a nation-wide campaign to raise the minimum wage by making recommendations to the South Korean government and prosecuting the businesses that violated the minimum wage system.  The KWWAU conducted a survey on the condition of 528 subcontracted women working as cleaners in 107 companies in nine cities.  Through the survey, it emerged that 23% of the workers surveyed received less than the minimum wage (421,490 KRW /$409 US per month).
During the campaign, it became clear that the minimum wage system did not protect workers employed in small and medium sized businesses; instead, the system was misused so that workers earned lower wages.  The KWWAU held a conference to publicize the survey results and to discuss 'How to Improve the Minimum Wage System from the Perspective of Unorganized Workers,' and to publicize the problems of the 'unrealistic' minimum wage system. 

In June 2001, KWWAU launched a campaign in nine different cities for the improvement of the minimum wage system. During June and July, more than 15,000 people signed the petition.
The KWWAU were the first to focus on increasing the minimum wage in South Korea. Later, other unions and organizations began to adopt minimum wage campaigns.  In 2002, many unions and civil organizations established the 'Minimum Wage Network' and started working to increase the minimum wage and improve the minimum wage system.  Recently, it was agreed that the minimum wage would increase by more than 10% every year. Currently The Network continues to carry out activities to improve the legal support system for minimum wage workers. 

Through the campaign for raising the minimum wage, leaders emerged from the ranks of the cleaning women.  Most of these leaders had previous experience fighting against threats by contracting agencies. They were very brave and encouraged and organized their co-workers. The sub-contracted cleaners convinced the public to sign petitions and continued to hold campaigns on the street.

Before this campaign, no one knew that there were people in Korean society who earned less than the minimum wage. The KWWAU raised the social conscience about the minimum wage system, bringing the issue into the sphere of social movement.  The major beneficiaries of improving the minimum wage system have been poor women.  KWWAU hopes that the income differentials are dissolved by improving the minimum wage system.