The parents did not raise Su to bow 90 degrees or more, Sakura Gakuin did. The difference between Himetan and Su was the nurturing they got. In the end it boils down to Amuse vs Akimoto.
When I played the video in low resolution, the moment the blue-clothed girl sing, I immediately know which one is THE QUEEN... her voice really has a kind of magnetic attraction that will charm everyone who hears her voice!