Don't be fooled by my mask

Cecilia is loved by everyone. She is also known as the "angel of school". However, she does not consider herself an angel. Rather, she believes she is the opposite and others only see the mask she is wearing. Then one day a new student joins her class. It seems like she cannot hide behind her mask in front of him. Will the new student be able to remove her mask? Will people finally see Cecilia's true face?