"Long hair group" is "장발족"(chang-bal-tchok) in Korean.
The men with long hair. American hippie culture, hippie group ( under the influence of히피족), hair style that was popular in 70s from the late 1960s. Government at the time dictatorship crackdown prohibits the long-haired man, was imposed one year in prison or 5,000 won more fines in case of violation.