On a cold, winter day, the first time Tanjiro accompanies his father to the town at the base of their mountain home, they encounter a very hungry, very angry, very lonely Genya.

The two eldest Shinazugawa children survived their families massacre, and parted on broken terms. They each went their own way, unknowingly leaving a surviving sister among the ashes. Yeah, I'm making a They Live AU for that one minor character who appeared in maybe five panels.

Giyuu is a hospital intern on the verge of getting fired. A patient shows up every week with increasingly absurd injuries.

"Muzan-sama, I did what you asked" - "The demon king is overprotective of his oldest creation" - "Please Uppe- ---- --ro, I won't do this again, please let me liv-" - "I'm sorry"

Kanae liked to talk a lot.

Sanemi wasn't suicidal; he was already dead.

Giyu cooked ohagi for Sanemi. Sanemi took Giyu out for salmon. or) snippets of post canon queerplatonic SaneGiyuu

Kanroji proves to be unnervingly disaster-prone, Shinobu is oblivious to the Love Pillar’s (distressingly obvious) infatuation, and there will be absolutely no smooching in Aoi’s Recovery Ward.

Sanemi found that Kanae was the Pillar he tolerated the most. She was his diametric opposite. Smooth where he was rough, patient where he was short tempered, kind where he was cruel. Those were differences he found odd, but endearing. They suited Kanae well. The one difference he couldn’t find endearing, the one that aggravated him more than anything else, was their stance on demons.

Urokodaki’s students are cursed, the slayer warned. None have survived Final Selection in many years. It is better if you do not go. He has lost so many children already. He will not wish to lose you as well. — “Then we will be the first,” Sabito vows. “Promise me, Makomo-san. You must swear to come back. Swear you’ll come back from the mountain."