[Crossover/Demon Slayer] I'm Tired Today, But Still Trying to Follow the Plot

A century later, Rui, Lower Moon One, has lived into the twentieth century. He picks up the diary he wrote not long after becoming a demon a hundred years ago and reflects on how people feel when they write New Year's resolutions... He hasn't managed to achieve a single one:

1. I killed and ate my parents, so I have to die.

2. I want a family: a strong dad, a timid mom, a monstrous older brother, a scheming older sister, and me as the younger brother who rules the family by force.

3. I want to steal a demon girl who is close to my older brother, then get my head cut off by him.

4. I want to be killed by someone everyone around them hates.

5. I want to apologize, then go to hell.

The Demon King and the Twelve Kizuki: We think at least the second one can happen--

Doma, mysteriously cut into pieces: ??? (What did I do this time?)

Rui: Who on earth stole my diary?!

--

Transmigrated Rui and demons who have strayed from the original story.

Everyone's a villain. Please don't read if that's not your thing.

Rui is doted on by everyone. Family bonds and friendship.

Includes reincarnation, and the Demon Slayer Corps won't be involved much.

Theme: Study hard and make progress every day.