Photo from here.
The government cracked down on female workers from the YH factory holding a strike in the opposition party headquarters, which left one woman dead. When Kim Young-sam used this to gain sympathy and began promising to bring down Park Chung-hee's government, he was stripped of his membership in the national assembly, which led students and citizens to protest violently in his hometown of Busan and Masan, which led to the argument between KCIA head Kim Jae-gyu and Park Chung-hee's underling Cha Ji-cheol on how to deal with such protests which led Kim to kill Park, which led to the ascension of Chun Doo-hwan and the Kwangju Uprising. I dealt with this in a little more detail in this very old, unfinished post.
An essay (I haven't read it yet) about women's labor movement and democratization in Korea is here.