Shiawasenanode Okamainaku!NewI'm Happy, so Don't Mind Me!; I'm Happy, so Don't Worry About Me! The Duke-To-Be Who Relies on a Romance Manual Wants to Catch His Fleeing Fiancée; I'm Happy, so Leave Me Be! The Future Duke Wants His Fiancée Back; Shiawasenanode Okamainaku! Renai Shinan-sho Tanomi no Jiki Kōshaku-sama wa, Nigeru Fiance wo Tsukamaetai; 幸せなのでお構いなく！; 幸せなのでお構いなく！恋愛指南書頼みの次期公爵さまは、逃げる婚約者をつかまえたい

Jade, the fiancé of Sophia (daughter of a Count), returns from the battlefield. As the son of a Duke, a handsome man, and an elite figure serving as the youngest-ever commander of the Order of Knights, he sends the local young ladies into a frenzy. Sophia is delighted by their long-awaited reunion, yet for some reason, Jade’s attitude toward her is cold and distant. To make matters worse, he kneels before the Imperial Princess right in front of Sophia and presents her with the medal he was supposed to give to his beloved. Sophia had spent her time diligently preparing to be a bride—suppressing the things she truly loved—just to be worthy of his noble status. Witnessing that shocking scene, she finally reaches her limit and unleashes the "tomboyish" side of herself she had kept bottled up, beginning to revel in a life of freedom. However... the secret behind Jade’s cold demeanor is that he is actually a "hopeless romantic disaster" who has gone completely off the rails after taking a "guidebook on romance" far too seriously...!? No more days spent suppressing her true self. The exhilarating, free-spirited life of a tomboyish noblewoman begins!!