I think there will be about 5 endings.

Ending 1. Dogday kills Catknapp.
Ending 2. Dogday and Catnap live together.
Ending 3. Dogday is also eaten by Catnap.
Ending 4. Dogday saves Catnap from the Red Moon
Ending 5. Dogday is also devoured by the red moon with Catnap

원곡: youtu.be/Mf39D4T0LHY?...

In fact, the AU was created from a song with the same title as the story, The Fox Sister. The lyrics go like this:

In the original story of the fox sister, the eldest son kills his fox sister with three mysterious gourd bottles, each with the power of thorns, waves, and flames. But, did he need to?

Dogday ends up leaving the place and living a long wandering life, but while he's gone, Catnap is eaten up by the red moon and hurts his friends, and when Dogday returns, Catnap greets him, but there was no one but Catnap.

After the Red Moon incident in M&M, Dogday told his friends what he had been through and what he had seen, but his friends didn't believe it and rather made Dogday a bad person.

He went into the mountain, trained himself in a strange force for three years, and went back to his original village, but the village was long quiet, as if people had left, and his sister greeted his brother in the abandoned house, which was once his home

The couple had their oldest son watch the barn, and sure enough, he saw his little sister eat away their guts. He told the couple, but they didn't believe him, and instead thought the oldest son had framed their daughter, so they kicked him out.