One of the many arguments that says that slave contracts don’t exist is that idols chose this life. And I suppose in one aspect, it’s true, as they signed it knowing what they were getting themselves into.
However, after you’ve dreamed of being an idol from such a young age and you’re recruited and signed on with a company to be a trainee at 12 or 13, that life is all you know. So you think nothing of it when you sign this “slave” contract. Yoona, from Girls’ Generation signed her contract with SM and it was for 13 years ! Ridiculously long for a contract, if you ask me.