My Crazy Housemate: What Makes You Happy

Leo was able to deduce now that Mia always fell asleep whenever she cried really hard and it was always a deep sleep. Well, a lot of people did but Mia's own was kind of special because even though she was sleeping, she still cried deeply even in her sleep. 

He slowly carried her to her room and dropped her on the bed. If he meant to look, he was sure going to see how exposed her chest was but that wasn't his problem at that moment. Nothing else mattered to him as he tucked her into bed and sat by the edge of the bed to look at her face. 

He had a really sad look on his face as he brushed some loose strands of hair away from her face and used the duvet to properly cover her body. 

He buried his face in his hands and sighed deeply. Everyday, he got to know her more. He got to know her deeply and it was obvious she had a really tough life. 

How did she survive it all?