Shristi is master's eldest daughter, she is not allowed to touch anyone since she has a illness called "touchakohan" it means that if she touch someone that perfect might have sickness too. She isn't allowed to touch the hashiras especially, since they are important to defeat Muzan.

Shristi stays in her room all day only sleeping. Suddenly Sanemi enter her room and move the transplant cloth from the side to look at her face, she looks at him with big wide eyes. He tied a red string in her ring finger to his ring finger. He then went outside and close the door a little and slept outside, without any blanket, pillow or anything. He was making sure you are okay while you are sleeping and he doesn't wanna stay away from you but he knows he can't touch you...

*Night..." With that he close his eyes not before glancing at you through the tiny opened door.