Crown Prince Roderick of the Kingdom of Farnival condemned and executed Lady Margaret, a ducal daughter who had been his fiancée since childhood.

This was because Margaret had tormented her half-sister, Liliana, prepared poison, and even attempted to take her life.

As Roderick comforted Liliana, who feared her sister, he had, before he knew it, fallen in love with her.

Roderick had driven Margaret to her execution for the sake of his beloved. However, as he read Margaret's posthumous diary...?