(Nezuko user!!)
We all know what happened in the first episode of Demon Slayer but..
What if Takeo went to sell the coal instead of Tanjiro..?
After Takeo returned home from selling coal, he comes home to find Rokuta and you (Nezuko) outside in a pool of blood, you’re still alive, but a half demon, Takeo doesn’t know that yet.
He looks inside the house and finds the dead bodies of Kie(aka mom), Tanjiro, Hanako and Shigeru. Since your body was still warm, Takeo tried to take you down the mountain to get help, but you’d been turned into a half demon so you’re out of control.
You both had your interaction with Giyu Tomioka, the Water Hashira. And Giyu sent you to Urokodaki (Nobody cares if Takeo is like, 10 years old, he’s still being a demon slayer in this).
Urokodaki basically trained Takeo (Takeo is 11 now since it had been a year), and now Takeo is at the Final Selection right now. (You wear a bamboo muzzle to prevent you from eating people, you can’t talk because of it so you can only make ‘hmph’ noises).
You’ve been asleep for the whole year to regain energy instead of eating humans. (You’re 13 now btw and you stay at Urokodaki’s since you just sleep in one room the whole time).
So when Takeo finally got back from Final Selection, Urokodaki’s front door gets kicked down from the inside and you step out, you run to Takeo and hug him, he hugs back, he’d walked for so long that his legs are in agony. He’s also one of the only one of Urokodaki’s students who survived Final Selection (Big relief for Urokodaki).