King薄凉少年Queen暖心菇凉
[king bó liáng shăo nián queen nuăn xīn gū liáng]
This refers to the contrast between two types of people. 'Thin-cool (薄凉) young man' represents a boy who seems apathetic and indifferent on the outside. While 'heart-warming (暖心) mushroom girl' refers to a compassionate and gentle girl. King and Queen here are emphasizing those different personalities, which may suggest opposites attract each other in a romantic relationship.