Set in 1986, the rough streets of Monga welcome a new face: Mark Chao as Mosquito, who arrives at a troubled high school and quickly earns respect on his very first day by refusing to bow to the taunts of Dog Boy, a position that catches the attention of Dragon Lee Rhydian Vaughan, the son of the feared temple-front boss Geta Ma Ju-Lung. The moment marks the start of a fragile alliance as Mosquito is drawn into the orbit of the temple’s youth, where loyalty, fear, and rivalry mingle in the humid air of Monga. With him stand Monkey Emerson Tsai and Monk Ethan Juan, along with A-po, forming the tightly bonded Princes Gang, while Ning Ko Chia-Yen—a woman connected to a brothel—begins to weave herself into Mosquito’s world.
Geta’s brutal code soon dominates the street hierarchy. He orders the finger severing of Doggy, Dog Boy’s father and a member of the rival Back Alley gang, for cheating on temple turf games. In retaliation, Dog Boy rapes Xiao Hui, Dragon’s girlfriend, and the Princes respond by kidnapping Dog Boy and torturing him to death. Geta wastes no time disciplining the five teenagers and delivers a brutal beating to Monk, who takes the blame out of loyalty to Dragon. The young Monk overhears, years later, his father and Back Alley leader Masa discussing Geta; their conversation hints at a hidden history of power struggles, including Geta’s earlier severing of Masa’s arm to seize control.
In 1987, Geta pushes the Princes into the mountains for a formal martial-arts and weapons-training regimen. A celebration brings Geta face-to-face with Masa again and with Wim-Kian, his bodyguard Wang Shih-Sian. Wim-Kian has crossed paths with Grey Wolf, a waishengren gangster played by Doze Niu Cheng-Tse, who is seeking to expand influence into Monga. Grey Wolf counsels Wim-Kian to topple Temple Front, sensing the shift in power, while Wim-Kian manipulates Monk, convincing him of the inevitability of the waishengren’s takeover. The web tightens as Wim-Kian orchestrates the assassination of Masa and Monk shoots Geta, leaving Mosquito to arrive too late and find Geta dying in his arms.
With Geta dead, Monk convinces the Princes to lay low in the Philippines while he remains behind to pursue his own inquiries. Mosquito confides in Monkey about his suspicions of Wim-Kian’s guilt, and Monkey’s vigilance is tested when he witnesses Wim-Kian and Grey Wolf in a secret encounter, only to be beaten into a coma. A despondent Mosquito seeks guidance from Grey Wolf, who instead nudges him toward his mother’s safety in the Philippines. Before Mosquito departs, he visits Ning one last time and shares a kiss, while he later uncovers Monk meeting with Grey Wolf and Wim-Kian. The Philippines plan appears to be a trap designed to wipe out the Princes.
Grey Wolf experiences a crisis of conscience and rushes to stop the ambush after discovering—through a postcard he sent to Ling-wan long ago—that he is Mosquito’s biological father. The tension culminates at Qingshui Temple, where Mosquito confronts Monk, unaware that Wim-Kian and his men are closing in. A chaotic battle erupts; Monk fights to defend Dragon, while a gravely wounded Mosquito pursues Monk through the streets and cunningly uses a hug to draw Monk into a moment of compassion, giving Dragon the chance to strike from behind. Dragon and A-po drag a delirious Mosquito away, leaving his fate unresolved and hovering between life and the next choice he must make.
The action cuts back to a poignant flashback—moments when the Princes Gang skipped class and slipped through the school walls. In that memory, Monk offers a hand to help Mosquito over the barrier, and Mosquito looks back one last time before choosing to join his friends again.
