Zoku Inaka no Kuro Gal JK to Kekkon Shimashita

Koichi leaves the city and moves to the countryside, where he marries Ichika, a kuro-gal. They devote themselves to making memories of their life together by having sex everywhere. Despite her appearance, Ichika is a tanned girl who likes the outdoors, and the two have plenty of sex in the fields
(Source: Melonbooks, translated)