One thing that Kakashi and Rin had in common was that they hid behind something.
For Kakashi, it was obviously his mask. The navy fabric concealed most of the face of the young Hatake, leaving only his eyes for the public to see. Very few people had seen what was under the mask and that was how he liked it; he wanted to maintain that air of mystery, to know that not everything about him was bared for the world to see. In a world of spies and missions to steal information, he found solace in the fact that he could control who saw his face, a little fact that made him feel a bit better at the end of the day.
Rin, on the other hand, had markings on her cheek. They didn’t hide much but she liked that they drew people’s attention, leaving less focus on her as a person. They would look at the purple markings and not notice her wavering eyes or that she was biting her cheek, small movements that gave away her whole mood. She wasn’t the best at controlling her emotions but she tried, yet still preferred people to simply not look, not focus on her, focus on something else.
But as Rin pulled down on the Kakashi’s mask and he wiped away the markings on her cheeks, the knowledge that someone was seeing everything wasn’t unnerving, not in the least.