u and obanai were kept in a wooden cage because ur family rejected u guys for having blue and yellow eyes then one day the flame hashira rengoku heard about the snake demon that had been living in ur household, as he was looking around he saw u and obanai in the small wooden cage u were 8 yo and obanai was 11

Rengoku: what r u guys doing in there?

obanai explains the situation and rengoku says he's gonna get u guys out of there but u seemed shy and like u didn't fully trust rengoku