Who is Juni from My Bloody Life: The Making of a Latin King and what is their importance?

Juni was like a younger brother to Reymundo. He loved to spend the night at Juni's house, which was suffused with a sense of love, but he could never understand why the younger boy with a stable home life was infatuated with the violence of gangbanging. To Juni..... it was just a game. Juni was not a gang member, but one day while walking with Reymundo, he flashed the King sign at a passing car. The Cobras in the car opened fire, and Juni bled to death in Reymundo's arms.