Dongzhu (Ha-seon Park), the daughter of the owner of the rice cake shop, is born tone-deaf and sings out of tune. At the age of 28, she is still unmarried, which makes her mother very worried. It turns out that Dongzhu has been secretly in love with a boy named Minxiu (Choi Jin Hyuk Kim Thae-Ho) in the class since high school, and she also joined the choir for him, which she is not good at. Later, Minxiu went abroad to Japan, and Dongzhu has cut off the news about Minxiu, but she still misses this old love in her heart. A few years later, Dongzhu, who had just lost her job, heard that the object of her secret love in her youth returned to her country and decided to pretend to be a high school student to sign up for a half-price discount for students to learn singing at the tone-deaf treatment clinic to attract Minxiu's attention. Shenhong (Sang-hyun Yun) is Eunju's music teacher. He determined that Dongzhu was a completely hopeless tone-deaf person, and the two sparks continued. However, in the daily contact, Shenhong learned about Dongzhu's purpose of learning to sing and began to devote himself to her special training. When Dongzhu confessed her love to Minxiu under Shenhong's encouragement, she learned that Minxiu and her best friend were already in love...