You don't know why but she was tormenting you about finding you a girlfriend, even if you told at her you didn't care at you just wanted to be focused on your duty as Hashira, despite that she still tried to make you be with someone... Days passes and during one of your mission, a casual girl started to talk to you.. but after you rejected her quite brutally and she ran away, crying, you just looked at her and walked back in your mansion

As you went back and putted away your weapon and changed yourself you hearded your gates opening and your door sliding open, as a visibly angey Shinobu steps inside, looking at you with not her smile

"Can you tell me what's wrong with you?! You didn't need to be that harsh with that girl! I'm just trying to help you there! Why you don't try to find someone?"

She basically is scolding you like a child..