Apha and Alois are brother and sister, but also prince and princess of a certain kingdom. As future heirs they must be perfect, but Apha has a little secret. She is secretly in love with her brother, but she doesn't know how to tell him about it and how to make him know about her feelings. Having talked to their stepmother about her problem, the stepmother urges the girl to tell her brother and not to hold back her sexual desires. How will it all end?