Part-Time Idol(2017)

Original title: 비정규직 아이돌

After creating a bunch of famous idols, a producer begins to question the whole process of making a star, so he goes on a break for a few years. Once he returns to the company, he gathers some trainees left on the back burner and tries to launch a co-ed idol group. The trainees undergo some peculiar training to debut in this group.