Blue Diner is a story of a Puerto Rican mother Meche (Miriam Colon) and daughter Elena (Lisa Vidal) living together in Boston and difficulties they face when Elena mysteriously loses her ability to speak Spanish, he first language. As Elena's language disappears, he boyfriend's (Jose Yenque) painting inexplicably appears at the museum where her mother Meche works.

Down-and-out Weslake is reduced to minding the counter at a San Francisco pawn shop when he stumbles onto a scheme by some of the boss's disgruntled misfit clients to rob the place. Rather than blow the whistle, however, he insinuates himself as the heist's mastermind.

T, as most of his friends, lives in a self-constructed 'house', built on top of an old building in the city. Their one passion is 'combat'. Combat is a dance/streetfight during which the contestants try to push each other out of the arena, while not allowed to actually touch each other. When drugdealers move into the neighbourhood and kill T's best friend he embarks on a mission to eradicate the drug-presence in the neigbourhood. His friends are reluctant to help though, knowing what happened to T's friend when he crossed them.