From the 1950s to the future, seven legendary directors each drew lots to direct a story about Hong Kong in a certain era. The title of "Seven Band" implies that directors with different styles and talents are like excellent musicians. When they come together, they can play a beautiful and resonant piece of music. These include Sammo Hung's "Practice", Ann Hui's "The Principal", Patrick Tam's "Farewell Night", Yuan Heping's "Return", Johnnie To's "Gold All Over the World", Ringo Lam's "Lost", and Tsui Hark's "In-depth Dialogue". Among them, Ringo Lam's "Lost" is the director's last work. "Practice": In the 1950s, a group of children who came to learn from their master practiced kung fu diligently under the strict supervision of their master. The tacit understanding between the apprentice and the master was formed in the shouting, and the day of being punished for being lazy could also become an unforgettable turning point in life. "The Principal": In the 1960s, the society was poor, but there were many students. A principal who forgot to eat while writing and the kind and elegant teacher Wang made a rooftop school the warmest home in childhood. "Farewell Night": Ye Jialin and Yu Yanfei fell in love in the still beautiful sunset of Hong Kong in the 1980s. The woman's family immigrated overseas, and the two had no choice but to bear the pain of separation, leaving only the memory of love. "Return": In the 1990s, the son's family immigrated, but the granddaughter temporarily stayed at her grandfather's house in Hong Kong because of her studies. The grandfather and granddaughter communicated across generations, which was interesting. In life, the generation gap was eliminated, the barriers were broken, and the family relationship was taken to a higher level. "Gold Everywhere": During the SARS period in 2003, the daydreams of prosperity of three ordinary citizens in the great era. The three often talked nonsense about investment plans, hoping to get rich overnight. After a lot of arguments, they always missed the opportunity to become rich. "Lost": In the New Year of 2018, the husband returned to Hong Kong to reunite with his wife and children. When he took old photos and recalled the past in the streets of Hong Kong, which was changing with each passing day, he completely lost his way. In the end, the memory unfortunately turned into reminiscence. "In-depth Dialogue": In the future, a mental hospital is conducting a study on schizophrenia. The four participants were so absorbed in the performance that their true identities could no longer be distinguished. Who was the doctor? Who was the patient?