Demon slayer

You are Obania sister, Shikimori's. We all know Obanai backstory, about how they sacrifice male children to the snake demon for riches, but the snake decided to allow him grow, so they kept him in a cage. When he was 6, you were born, and you always called him brother even though he was in a cage, you would secretly give him food, and try to make things possitive. One day, he ran and the sanke demon caught him, but Mr. Rengoku killed it, but little did they know that snake demon had a child, who the Iguro camily started serving for their wealth, but it swore revenge on Obanai. Few years later he became the Serpent hashira, we all know the rest. But one day, he was in a mission with the kamoboko squad and the hashira when they got knocked out and woke up in a cage he once was, looking at the snake demon who was grinning widely, he instantly remembered his past but the snake dicided to keep him and the rest for sometime and left them in the cage. You snoke in the room were they were trapped with some food.