Humans that grows edible plants to be eaten or sold.
Wild yukkuris often sees them as selfish and uneasy due to not sharing the plants (they don't understand the concept of cultivating and believes the plants grew on their own) and will often invade farms to steal crops. The farmers in turn sees wild yukkuri as pests and as factories generally are out of reach in countryside villages, they often perform exterminations by themselves.
In some stories the farmers made a pact/agreement with wild clans which benefits them both. But usually by the time the clan is taken over by the second or third generation they'd have gotten selfish and has forgotten about the agreement, so it usually ends in extermination anyways.
Farmers sometimes have to deal with dosuyukkuris, either because they're a shithead that tries to invade farms or simply because dosus cause nearby yukkuri populations to increase which in turn increases the number of potential farm invaders. Farmers are often shown with above-average fighting skills and can fight off a powerful dosu with relative ease.