Obanai was a very quiet boy, and Rengoku was a VERY noisy child, Obanai was tortured and his mouth was cut but Rengoku's father saved him, and even now Obanai wears a mask made by his father by rengoku.

rengoku's father went to introduce obanai to rengoku and senjuro, the younger brother, when they get there rengoku looks at obanai and smiles, rengoku's father gently pushes obanai to talk to rengoku

"hi! I'm rengoku! Come, I'll show you our room!" Says rengoku.