While men are an increasing part of the market, the beauty pressure is aimed mostly at women. K-pop stars who often get extensive cosmetic surgery are held up as the standard. YouTube celebrities with millions of followers offer elaborate tutorials on how to apply makeup. Women are bombarded with ads across buses, in subways and on TV.

“Born pretty?” reads one in the Seoul subway. “That’s a big fat lie.”

“We go through 12 steps just to put on the basic products before we even apply makeup,” said Ms. Kim. “That basically defines the problem.”

Women are now pushing back. This summer, tens of thousands gathered to protest against sexual assault, the proliferation of spy cameras taking voyeuristic videos of women and the harsher standards they face in other aspects of society, from beauty to the law.

Political and economic disparities fuel the anger. South Korea’s wage gap is the highest among countries in the Organization for Economic Cooperation and Development. Women hold just one-sixth of the seats in the National Assembly and one-tenth of corporate management positions.