Munou Saijo wa Akujo ni Naritai ~Gimai no Migawari de Totsuida Reijou, Koushaku-sama no Dekiai ni Kizukanai~

Despite possessing extraordinary talent, Avril has spent her life enduring relentless mistreatment from her own family, who cruelly branded her as incompetent. When the time comes for her half-sister to wed, Avril is forced to serve as a substitute bride, sent to marry a duke rumored to be a lecherous old man. However, upon arriving at her new home, she discovers that her husband, Dylan, is nothing like the malicious gossip suggests. He is, in fact, a strikingly beautiful young man whose true nature stands in stark contrast to his scandalous reputation. Dylan harbors an unexpected desire: he wishes to marry a villainess. Recognizing a unique opportunity, Avril eagerly embraces the role, throwing herself into the part with absolute gusto. Their arrangement includes a contractual divorce after three years, which promises Avril the freedom she has always been denied. While those around them are utterly bewildered by this mysterious and brilliant woman who so enthusiastically plays the wicked wife, they gradually find themselves captivated by her undeniable charm. Yet, amidst her spirited performance, Avril remains completely oblivious to the genuine devotion her ducal husband holds for her.