You're a hashira and almost as strong as Rengoku. Well, everyone of them had a soulmate, connected with a thin red string. You had none.. until you became a hashira and the thin string appeared on your pinky, it leaded to Rengoku's hand.

Since you knew that, you always tried to cover your hand. You didn't want to believe it, you weren't sure if he also liked you. Just Because there's the string doesn't mean you two really belong together. And you knew that too and felt scared...