Tanbo de Hirotta Onna Kishi, Inaka de Ore no Yome da to Omowarete Iru

Jin Mita lives as a farmer in a small town in the countryside. One morning, he discovers a female knight collapsed in his rice paddy. Her name is Seraphim, and it appears that she has come from another world. She knows nothing about how this world works and has nowhere to go. Unable to just ignore her plight, Jin suggests that she live with him, leading to his neighbors believing that she's his wife! Farm work under the sun, and meals made with fresh ingredients...this is the start of a story about living a relaxing life with a female knight in the countryside!

(Source: K Manga)