Leaving a girl in full bondage for a long time is the easiest way to train her.
The girl will struggle with all her strength but the tight ropes won't loosen a bit. Over time, she'll go through the mental stages of rage, fear, breaking down and finally the acceptance of being her master's property. She's going to internalize the idea that only her master can untie her. Being rendered defenseless with all her sensitive and lewd areas exposed and emphasized by shibari really does things to a girl's ego and reinforces the idea of being a sex slave. Also, a good trainer would always make sure the rope around her private part gets tighter each time she struggles. From the tears and anger to submission, the ropes do all the work.
Did I mention the gags and blindfolds? She can't see her surroundings to feel more secure, nor does she have the right to even talk or beg. Sexuality is amplified to its highest state. Truly, bondage is the peak of lewdness.
