context: The story takes place before the early year of 2000 when Laughing (Michael Tse) is an undercover cop, but because of a drug case, Inspector Poon (Felix Wong) has been trying to track him down.
  Laughing is supposedly an undercover cop who has infiltrated a triad organization. However, before he became a cop, Laughing was a member of the triads and worked for the triad leader Lai Tin-yat, aka Brother One (Anthony Wong). Brother was very good to Laughing, and Laughing looked up to him as his elder brother. In order to strengthen his business and illegal activities, Brother One arranges for Laughing to join the Police Force and become his mole to gather information about the plans and counter-plans for operations by the police.
  Laughing graduated from Police Academy with outstanding results but before he was assigned to a post as a police officer, his "bad boy" image attracted the attention of the Head of District Anti-Triad Squad, Superintendent Sin (Yuen Biao) who arranges his assignment as an undercover cop to infiltrate the mob syndicate.
  Laughing is now a "double" agent. Brother One was happy with this turn of events as Laughing was assigned to infiltrate the mob of his triad rival sibling Zatoi (Francis Ng), who tries to make life difficult for Laughing. To further complicate the situation, Laughing falls in love with Zatoi's sister, Karen (Fala Chen).
  How will Laughing contend with the law, the triad brotherhood, and his love affair? No matter which camp he sides with, he is doomed to be a traitor to the other. Which path will Laughing ultimately choose to follow?
question: Who persuades Laughing to join the police academy?
answer: Brother One does.