The series revolves around the journey of music producer Wang Po Han and his assistant An Yi Qi to find the copyright owner of the mysterious song for their artist, A-Lin. They also came across a diary belonging to K who is the producer of the mysterious song and traveled into the life story of K through the diary. The diary tells the story of K and Cream, two orphans who journey through life and share experiences in sadness and joy together. However, K is diagnosed with fatal leukemia cancer. Knowing that Cream's biggest fear is to be left alone, K keeps the fact that he has terminal cancer a secret.

On Green Island in the 1950s, the female thought prisoners chose to fight for freedom, but were more forcefully suppressed by the authority. They held on to their beliefs and hoping for true freedom to come.