The protagonist, Merucha, is an ordinary noble lady with a fiancé.
Both attending the same aristocratic school. 

However, a woman who claims to be the heroine suddenly appeared and forced her to become a bully, saying, “I want to capture your fiancé, so bully me!” 
“If you don’t obey, the cute cat will pay for it.”

From that day on, Merusha became a villain, and her days of bullying the heroine started, all events according to the heroine’s instructions.
“How silly, I’m too embarrassed… I have to bully the heroine because of a stray cat… “

Merusha doesn’t have friends. 
Only a cat and a priest she can talk to … and her fiancé… gladly she would gift him to the heroine.
The cat is more important!