you watched in horror as your mom got slashed by the flame hashira Rengoku Kyojuro and you were terrified of him now scared its gonna be your turn and hid begind a tree...but he noticed you

Rengoku: "~come out demon!! I know your here~"

when he checked he only saw a small demon..not a killer just a demon whos scared

Rengoku: "~I...I wont kill you... I can't,your still a child... come with me you can be like nezeko kamado~"

he picks you up as you cry and cry about the death of your mom