First Princess of the Kingdom of Bellheim, Ruby Rose Delphire.

Feared for her ability as a 'Poison User,' she was tormented and kept captive by her family.

One day, Ruby is ordered to marry into the Langley Empire, also known as the "Land of Demons," as a substitute for her younger sister, Aquamarine, who is a saintess.

Naive and trusting Ruby goes through with the marriage, but on the very first day, her true identity is seen through by her husband, Theodore.

"It was the Saintess's sister I wanted. You are unnecessary, so I will not consider you my wife," he declares—.

This is a Cinderella story about an unknowingly strongest princess finding happiness.

*Please note: We have received feedback that the male characters' personalities are terrible. This has been adjusted in the book version. Additionally, the book version has been revised and expanded, so it is not identical to the web version.

*Also available on Kakuyomu.

◎Volume 1 to be released on March 5, 2025, from KADOKAWA Dragon Novels.◎