When the Villainess Seduces the Main Heroine manga volume 1 features story and art by Kasai Fujii.

When the crown prince announces he's breaking off his engagement to the infamous Akuya, his spurned fiancée wastes no time in turning her seductive words of passion to her actual target—Sei, a commoner who worked her way up through the ranks with her wit and charm alone…and is also the very girl the prince dumped Akuya for! Sei's about to get a taste of what a real lover's like in this steamy tale of two girls who traded in their Prince Charming for each other instead!