K-pop idol stars’ way of greeting is very polite. They seem to bow deeply at a 90 degree angle all together like singing in chorus. Bowing deeply is not a traditional greeting manner in Korea, however, it is considered as a gesture expressing one’s respect from some time ago. Considering that most idol stars make their debuts at early ages, they naturally become to learn bowing deeply whenever they meet seniors. As a result, it is to be considered as one of greeting manners, which everyone follows in the entertainment world. However, one interesting thing is that idol stars courteously greet not only seniors but also older people even in the same team. They look like