The narrator, who owned a traditional farmhouse, lived alone. One day, anon came across a family of yukkuri in the field. Instead of the usual response to a home invasion, anon decided he will take reimu and her family in.
Anon's intention was to use the yukkuri as a waste processor by feeding reimu garbage, and use the yukkuri's excrement (including the yukkuri, should it expire), as fertilizer. Surprisingly, reimu and the koyukkuri were a nice, amiable yukkuri family, content with eating the humans' munch-munch while taking it easy all day. Later on, anon got them badges. Anon's friends who visit the farm would be amazed at the ingenious system (it seems that not all yukkuri would not submit to this degradation).
One night, a remilia entered the farm, and attacked the reimu family. The reimu tried to drive the predator off with a stick held by her braid, but it was useless. The remilia managed to snag one of the koyukkuri before in turn got caught by anon's net.
Incidentally, remilia's meat filling is delicious. There were too many to eat, and so the rest ended up in the compost heap.
Some time passed, the koyukkuri grew up to be an adult, and the mother has passed away. Anon decided that to have more yukkuri, so he procured a marisa to be reimu's partner. The marisa turned out to be such an arrogant paste-for-brains, so it was discarded right after getting reimu pregnant (didn't even kill it for fertilizer, but took away its hat before throwing it out the gates, leaving its fate to the wilds).
The reimu had marisa koyukkuri as well as reimu koyukkuri. They turned out to be fussy eaters at first (must have inherited that from the marisa), though their attitude got better as they turned older. Since winter was coming, anon fixed up the compost heap they lived in into a livable shelter so they can survive the cold months (letting them in his house is out of the question).
Reimu recalled in a dream her mother, and how she is happy that they have finally found the sought-after Easy Place (the garbage heap) after so much hardship.
In the end of the story, two years have passed, and reimu had passed away. Her koyukkuri had grown up, paired up with each other, and had koyukkuri of their own. All of them still living in the narrator's farm, taking it easy.