Spiritual Friend

Lei had a strong connection between her and her mom more than her dad and always had the time to visit her sick Mom. But when her dad found out, he forced her to stop, which then, torn the family more apart.
3 years has passed and she now lives with her friend after her dad commits suicide. She now once again has the time to go see her mom like the old times but when she arrived, the hospital was blanked empty.
Just as she was giving up hope fast,
She hears footsteps which causes her to follow them to only meet up with a wounded pale green-haired boy known as Ao.
Now she doesn't hang out with her mother but hangs out with Ao which she later discovers new secrets about the hospital, her mom and Ao.