And...done, I'm not a good fan of this story, but this is pretty much straightforward and (largely) textless, so here we go.
Back to the story: I still think that this Marisa didn't take enough karma, Reimu - although stray, she didn't do what a typical stray does, but based on the post #80212, I imagine that though she loved Marisa, the second reason she decided to get in the house was to refresh with a pet yukkuri and become one like her "husband". The koReimu didn't show much, in fact she didn't show anything at all, so no comment, while the koMarisa is just a typical koyukkuri, so I don't dislike it either.
The reason I hate this Marisa is that her owner really loves her, you could see post #80209, she buy so much toys, clothes, food (can't understand what is the meaning of that kata, but I'm pretty sure it's not low-grade food); post #80210, she plays with her, not neglecting or abandoning her or don't care about her; post #80235, she even has a yukkuri calendar, and after kicked that thing out, she's also buy a new one. So what does that mean? It means that she absolutely loves yukkuri, most notably pet yukkuri and a good one. And what did that thing do to her? Betrayed her trust and refreshed with a stray. She came from a shop so she must know that it is forbidden to interact with strays, let alone refresh with that. So yeah, this thing deserved all of this.