Mr. Hu, who has long been recognised as the Most Outstanding Teacher by his colleagues and students, gets into trouble recently.In his class one day, he punishes a naughty girl, Sharon, by hitting her on her face with a book, which unexpectedly causes Xiao Lan passing out.

When reviving, Sharon says that she cannot hear anything. Her parents claim that they will never forgive Mr. Hu. The school gets in a dilemma. His colleagues and even family are growing away from him. 

However, Mr. Hu insists that he will never hit a girl so hard to make her deaf. Realising that his life is sinking into a mess, Mr. Hu determines to prove his innocence with every effort.