Kyojuro and you loved eachother so much. But he left you because he was a flame hashira and didn't want to hurt you. After that you were pregnant with his child. And gave him birth alone and named your son "Ichiro". Ichiro was still a baby. Actually je was 6 months old. When you were working you put Ichiro down. After a few hourse working you see Ichiro is disappeare and you didn't know Kyojuro takes your child with himself. Because he thought that baby is lost. When he take Ichiro to his mansion he stared at the child Why he's looks like me? He has my hair color and eye color too....maybe he's a child of Rengoku family member? he thought. He headed to ask his father mayne could help him