Anko 2949: "Stray Reimu," by Bayajiru-aki
A stray Reimu on the street begs passers-by to take her in as a pet. When one Mister refuses, she begs him to at least take her little one, a weak, sickly little Reimu. Impressed by her devotion, Mister says he’ll adopt the koyukkuri, but warns Reimu that she can never see her child again. Reimu agrees.
Mister nurses the starving koyukkuri back to health. Some weeks later, he finds the mother Reimu in his yard, having spotted them when they were out walking and followed them back home. He tells the mother to leave. However, the next day, she’s back, pressed against the window, watching her child inside the house. The little one recognizes her and begs Mister to let her mother inside. He doesn’t want to, but finally he gives in and opens the window.
He does, and the stray Reimu immediately attacks her child, jumping up and down on her, accusing her of taking her mother’s place and becoming a pampered pet while her mother has to struggle on the street. Mister throws the stray out and tries to heal his pet, but the attack has broken her and left her a gibbering idiot.
The stray Reimu comes back and suggests that Mister keep her as a pet instead. She refuses to recognize the little Reimu as her child, but the child seems to still love her mother and tries to get close to her. Mister tells the stray Reimu that anything she does to the child will be done to her in turn. Despite this, the Reimu stubbornly continues to abuse the koyukkuri at every opportunity.
Mister no longer feels any love for the ugly, broken thing that once was his pet. He tells the stray Reimu to do what she wants to, and she promptly jumps on her child and mashes her to a pulp. In return, Mister abuses her until she’s unconscious. When she wakes up, he feeds her the koyukkuri’s remains. Then, as her final punishment, he maims her with a knife and lets the stray yukkuris in the park eat her.