In 1980s Hong Kong, troubled youth Chan Lok-kwun, a mainland refugee, struggles to survive in the Kowloon Walled City by joining underground fights. Betrayed by crime boss Mr. Big while trying to buy a fake ID, he steals drugs from him and seeks refuge in the Walled City, where he encounters Cyclone, a compassionate yet authoritative crime lord.
YUM Investigation is a detective agency that specializes in the supernatural. With their new member Kojiro, the agency investigates a developer who dispatches evil spirits to scare away the residents of an old building. When they discover that the spirits were created by a sinister “spirit refiner”, the investigators must use every trick up their sleeves to crack the case.
“CHUNG LUI SOCIETY” is a boxing gym founded by the former legendary Muay Thai champion CHUNG Lui (Louis KOO), who is dedicated to training professional fighters. Despite the gym's struggles, he remains committed to his lifelong philosophy of never backing down from a challenge. Businesswoman Elsa (Louise WONG) discovers that her boyfriend Daniel (CHAN Charm Man Peter) is cheating on her with Macau's female champion, Surewin (Chrissie CHAU). Driven by her competitive spirit, Elsa vows to settle their score in the ring. Upon learning that Surewin was Lui’s former student, Elsa seeks him out to train her at his gym. There, she encounters MOK Ka Lei (Gigi LEUNG), who had previously clashed with her during an advertisement shoot. After leaving the entertainment industry to support her family, Ka Lei attempts to make a comeback, with the help of her friend LAM Pik Chu (Harriet YEUNG).
