Binbou Kishi ni Yomeiri Shita Hazu ga!? Yajin Reijou wa Koutaishihi ni Natte mo Ryuu wo Karitai

I married him because he said we'd hunt bears, but he turns out to be the emperor's illegitimate child?! I had no idea!! Despite being a marquis's daughter, Ralphine grew up on a rural estate for reasons unknown. With her exceptional athletic abilities and competitive spirit, she is known as the "Wild Lady," renowned both as a hunter and as the leader of the village children. At the age of 13, she reluctantly attended her debut ceremony at the imperial palace as a noble's duty, but her unruly behavior caught the eye of knight Selmiane, leading to her being married and sent to the imperial capital. However, this supposedly poor knight is actually the illegitimate son of the current emperor—!? A wild young lady and the strongest knight hiding his true identity embark on a doting, rags-to-riches adventure! (Source: Shufu to Seikatsu Sha, translated)