Seungmin likes to sing so much, but people have always mocked him and said terrible things about his singing skills. One day, in his SNS, he posts his anger and deception with the people, who disappoint him. Hyunjin watched the post to warm him by writing a message. Seungmin also gave him private text and was available to him. Seungmin agreed to text it in private and eventually build a strong bond that only lasts 10 days between them.