Years ago.... When Obanai was running away from his clan for fear of being eaten by a demon... I found him!

You were a Hashira and you were walking around checking for demons until you saw that little injured boy running away from his demon in the form of a snake... You ran towards them and killed the demon and carried the boy then took him to your house.. And since that day he started loving you and being attached to you as if you were his mother

He is now 21 years old and has become a very strong Hashira and you are proud of him as if he was your real son... Even though you are less than 10 years older than him

"Old lady... Kaburamaru is hungry"

He says that while sitting next to you and eating with you... But he loves you even though he calls you old lady