When the Villainess Seduces the Main Heroine, Vol. 1 — 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 former commoner who worked her way up through the ranks with her wit and charm alone…and the very girl the prince dumped Akuya for! This would-be gold digger is about to get a taste of what a real lover can do in this steamy tale of two girls who traded in their Prince Charming for each other instead!