One Day was an eleven-member South Korean band. It was started by Korean musician Park Jin-young. After performing as one group, it was splintered into two separate bands called 2AM and 2PM respectively.
A documentary called Hot Blood Men[1] captured the group's rigorous training program. In this documentary, former member Jay Park (Jaebeom) finished at the top spot and received the most fan votes. It also featured the elimination of three trainees from the group: Lee Swichi, Jeong Jinwoon, and Yoon Doo-joon who were all cut.[2] Jinwoon replaced Im Daehun upon the latter's withdrawal. By the end of the training process, One Day had been reduced to an eleven-member group.
