El polaquito (2003)

At age 13, a street kid known as "El Polaquito" makes his living mostly by singing tangos on Buenos Aires commuter trains. He falls in love with a 16 year old prostitute, also working for the Mafia controlling child exploitation in one of Argentina's busiest train stations. He tries to rescue her from this cruel life with no future. But to do so, he must confront the ruthless adult gang leaders, as well as the young kids who protect them, believing that this Mafia is truly their only option.