So I just read the anko, here's the summary:
Marisa and maricha were stray yukkuris father and child. One day they were rub-rubbing on a cold, raining winter night in their cardboard home, trying to fend off the cold. As a single parent, Marisa wanted to keep maricha from danger and let her take it easy as much as possible. This is when male anon, in full rain day gear and eating a lollipop, stepped in.
Marisa was alarmed by anon's presence, as humans more often than not approach stray for the sole goal of abyuse. Anon then opened his mouth, asking if they were cold. Marisa cautiously answered yes after anon insisted for an answer, to which anon responded by reaching into his pocket and showing Marisa and maricha a picture on his smartphone.
The picture was of anon's pet Reimu, an immaculate, beautiful pet yukkuri with very long black hair, resting gleefully on a cushion while holding up a takoyaki.
Anon asks if they think Reimu is taking it easy, to which the two answered yes. Anon then described how nice the being indoors is on a cold, wet day like this, and how enjoyable a warm meal like takoyaki is. Marisa felt disheartened as both of which are way beyond stray yukkuri's reach.
Anon then showed the two a picture of pet Reimu resting on the side of a large dog (presumably golden retriever, based on description) like good friends, taking it very easy. Anon says it's his cute family dog, and described how warm and nice the doggie is while pointing out the worn out, barely functional old towel Marisa has. Of course Marisa and maricha's hearts sank further
Anon keep showing other pictures of Reimu taking it easy, including walking in the rain in full pet yukkuri rain coat (not having to be afraid of the rain) and her in the arms of anon's little brother like good pals (not having to be afraid of humans).
This is when Marisa realized anon is not there to abyuse them physically, but to bully them: showing them the good life other yukkuri has that the two never can or will obtain.
His intent busted, anon decided to show the two one last picture: it was one of anon's brother and Reimu eagerly waiting for hot cakes to cook on a hot plate, with honey, butter and ice cream on the side ready to be served. Anon also revealed that he's out in the rain to buy his brother's favorite chocolate sauce, and that he's actually Marisa's 'neighbor': he lives in the house just next to their cardboard box. A yukkuri's heaven and hell was literally a wall apart.
The sweets sweets they'll never have, alongside the memories of maricha's mom stray reimu dying from malnutrition before doing please eat up, finally gave maricha a breakdown.
Maricha recalled everything anon showed them, declared how unfair everything is and demanded to become a pet yukkuri like Reimu.
Satisfied with seeing the reaction, anon declined light heartedly before heading home.
The story ended with a heartbroken maricha and Marisa, both crying, and Marisa apologizing for giving birth to maricha as a stray. The sound of their wailing was washed away by the sound of the heavy rain.