Shank (2010)

"SHANK presents a stark, unflinching glimpse into a dystopian urban future, where firearms have been replaced by the brutal edge of knives. In these bleak streets, adolescents wield blades with reckless abandon, yet among them stands the Paper Chazers, a gang driven by ethical principles. Trading scavenged food for cash, they navigate the chaos with a rare moral compass. However, Junior, a member of the Chazers, faces a harrowing choice after witnessing his brother's murder: pursue vengeance or adhere to the gang's unwavering code of ethics."