In the recent episode of "PD Notebook," "Idol School" contestants opened up about the reality survival show's unfair treatments and problems with the contracts.

Lee Hae In also shared a lengthy post revealing the predicaments on "Idol School." In her interview with "PD Notebook," she said, "At first, they told me not to go to the audition venue where the 3,000 people were trying out. They told me 'You don't need to go,' so I wasn't preparing. But the day before filming, the writer in charge told me that I needed to go because I was relatively well known."

The hopeful went on and disclosed that if the candidates are asked where they tried out, they would not be able to respond since they had not undergone an audition. Lee Hae In added that most of the 3,000 hopefuls who tried out were only used for the show.

One anonymous candidate revealed she was told by the production staff to say that she went to an audition with 3,000 people even though she was not.

Moreover, Lee Hae In confessed that the quarters they slept in was not in its pristine condition. She detailed, "The pink lodgings that were shown in the studio were very recently constructed, so the paint smell was very strong and the ventilation there wasn't good. If you [shake] a blanket once then a huge amount of dust would come out. It was to the point that girls with sensitive skin got red skin diseases all over."

Other contestants revealed that there were candidates as young as 12 years old. 

"There were girls there who were just 12 years old. They're still growing so don't they have to eat? They'd cry because they weren't given food. My head hurt and I'd think, 'What kind of filming set is this?' There was one point in the middle when some people broke a window and escaped. They were so stressed out from being locked inside that they broke the screen and glass and escaped," a trainee said.

"We were always indoors, so we had no idea whether it was daytime or nighttime. We'd go get ready when they told us to, eat when they told us to, sleep when they told us to, and get up when they told us to," another one said.

One contestant claimed her health got worse and didn't get her period like many others. Others, on the other hand, had bloody residue for as long as a couple of months.

Meanwhile, an "Idol School" producer said that the candidates are eating well to the extent that concerns about them gaining weight were increasing.

The producer added, "I'm not sure about that exactly because I wasn't in charge of it. I don't believe there was manipulation."