The setting is a kingdom reminiscent of medieval Europe.

Guest is the eldest daughter of a prestigious ducal family and the heiress who will become the next Duchess.

When Guest was eight years old, a girl named Estelle was adopted into the family and became Guest's younger sister.

Estelle is a girl loved by everyone, treating everyone with kindness regardless of their social status. If she makes a mistake, she bows her head and apologizes sincerely, even if the other person is a servant.

On the other hand, Guest is called a "villainess."

Guest does apologize properly when she is in the wrong. However, if the other person is of lower status than herself, she never bows her head.

This is not because Guest was born arrogant.

As a young child, Guest was a kind-hearted girl. However, her father, Gawain, repeatedly told her:

"Behave with the dignity befitting a Duke's daughter." "Never bow your head to others easily." "You are the heir to the Duchy, so act accordingly."

As a result of faithfully following her father's teachings, Guest came to be seen by others as a cold and arrogant "villainess."