ポンコツ王太子のモブ姉王女らしいけど、悪役令嬢が可哀想なので助けようと思います～王女ルートがない！？なら作ればいいのよ！～@COMIC

Lucia, the first princess of the Kingdom of Faticia, meets Alicia, the daughter of a marquess, who laments that she never wants to be a villain's daughter. Lucia takes pity on Alicia for her future engagement to Lyle, Lucia's half-brother, leading Alicia to confide in Lucia that her engagement will be broken off and lead to her execution. To prevent the death of her father, the king, and an epidemic her brother starts, Lucia shift into action! A ten-year struggle that shapes the future of an NPC princess and a villainous daughter in a sim dating game begins! (Source: Manga Plaza)