"Wallpaper" 

It was a love poem. Not an overly dramatic one, but one could sense a genuine affection and longing in it. 

Morning to you 

Winter has come 

I miss you 

When will you come? 

Zhao Yang's eyes couldn't leave these four sentences written using finger and a foggy glass wall as the base. 

The poem was simple, but the scenery it made just touched his heart. It was the first time he ever saw someone writing a poem on a glass wall like this. 

I miss you. When will you come? 

It portrayed the writer's longing to see whoever read the sentence. It also meant that the writer had always been waiting for the one reading it. 

There's only one person who would do so. That person was always in this place even before the sun rose from the east. This person would quietly clean everything and left once she was done. 

Her bright, orange uniform looked like the sunset, pleasant to the eye. 

It is Lai Jiayi.