The story takes place in a magical world called "Fairy Tale Kingdom". The energy for this world is provided by the stars of happiness floating in the sky. Unfortunately, the stars of happiness have disappeared one after another in recent days. If this situation continues, the Fairy Tale Kingdom will disappear one day. In order to avoid this, the queen decided to send three magic pets to the human world. They have to find three girls who are qualified to become idol princesses and entrust them to help the Fairy Tale Kingdom collect the stars of happiness. These three people are Yukimori Apple, Takagi Leila and Sasahara Nazuki. Under the blessing of magic, the three girls are able to temporarily have the appearance of adults. They bring happiness to people through their singing and dancing. Because the transformation lasts for a very short time, they are also called "mysterious beautiful idol princesses".