Ossan Kishi ga Inaka de Mattari Slow Life wo Okurou to Shitara Konyaku Haki Sareta Koushaku Reijou ga Korogari Kondekita Ken

Former irregular knight, Leonardo Bacchus, has been made the magistrate of a small village as a form of forced retirement after turning forty. Impressed by the village full of kind-hearted people, abundant nature, and delicious local food and drink, Leonardo thoroughly enjoys this simple lifestyle, far preferring it to the glam and glitz of noble life. However, one day, an uninvited guest arrives. In the middle of a rainstorm, a young girl shows up, demanding that he marry her. After letting her inside, she ends up collapsing into his arms... Source: Renta!