A music film about a teenager (Mia) who is a singer/musician from a small town in search of her father, a down and out rock-n’ roller.

Twelve-year-old Mia lives in poverty with her mother, Lacy, in a mobile trailer in Death Valley. She has a pet turtle, Aristotle, and a piranha necklace, which she believes was left behind by her father, Tommy. The frontman for the band The Piranhas, he left a long time ago. Smart, cynical, and tough, Mia endures torment from her classmates and neglect from her drug-addicted mother. Mia is blessed with a talent for the guitar, a soulful voice, and a talent for writing songs, but her mother refuses to let her sing and Mia seems to lack the confidence to ever do anything with her gift – early in the film, she records herself singing only to delete the tracks.

Lacey brings her boyfriend Spencer to the mobile home, who shows an interest in Mia’s music – and in Mia herself. Grabbing her guitar, turtle, and Spencer’s keys, Mia steals his Cadillac and heads to Los Angeles. Her journey is quickly cut short when the car runs out of gas. She walks to a gas station and obtains a jug for gas from the cashier, an irate man who has a piranha tattoo. He recognizes Mia’s necklace and tells Mia that he lived with her father in L.A. at a place called the Paradise Apartments.

Mia steals gas but at the last minute abandons the car and jumps onto a nearby freight train. She journeys by train to L.A., accompanied by a rotating group of itinerants: vagrants, migrant workers, gangbangers. She reaches L.A., only to find that Paradise Apartments is a hip, posh place where no one has heard of her father. In a record store, she finds an old Piranhas’ CD and, in the liner notes, finds an address for “Paradise Productions”. This takes her to a much more rundown apartment complex, where a neighbor tells her that Tommy has moved. However, he mentions a bar where Tommy can usually be found. At the bar, she’s told that Tommy was spotted walking a dog down by Ocean Park.

Mia goes to Ocean Park where she eventually finds Tommy walking a dog (she recognizes him because of the piranha tattoo on his arm).  She follows him and even picks up the dog droppings which Tommy abandons. Tommy spies her and tells her to get lost. Mia continues to follow him as he takes the dog back to a big beach house. He leaves the dog there (we later learn he’s dog sitting) and Mia finally confronts him. Tommy tells her he isn’t her father and drives off. Mia wanders off and ends up crashing with a bunch of homeless teens, who she dazzles with her music. But when she wakes up, she finds she’s been robbed: the guitar is gone.

Feeling defeated, Mia contemplates returning home. She finds Tommy on Facebook and notices that he’s playing at an Open Mic event that evening. She goes to the bar where she sees Tommy play. He’s terrible, but at least two people think he has potential: Mia herself and a producer named Gregory, who gives Tommy his card. Outside the bar, Mia sings for Tommy, who finally cracks and offers to get her some food. When it turns out he’s broke, Mia takes his guitar and busks for change. When Tommy learns she has nowhere to go, he reluctantly takes her home.

 

Tommy is living with a burlesque performer named Kate, who is not pleased that he’s come home with a twelve-year-old girl. Mia spends a few days with Tommy and Kate, but it’s clear that Kate is threatened by her and even tries to set Aristotle free. As Mia runs off to find him, Kate gives Tommy an ultimatum: her or the girl. Mia finds the turtle but also sees the homeless kid who stole her guitar. When she tries to get it back, it leads to a fight in which the guitar is destroyed. Mia steals the kid’s skateboard as he runs away. Tommy appears, having decided to help Mia. All this time Lacy has been calling and Mia finally answers the phone. Tommy talks to her and it’s clear Lacy doesn’t know who he is. She gives Mia twenty-four hours to come home – or not to bother returning at all.

Tommy finds a motel for them to live in and eventually gets her enrolled in school. They continue to bond and Mia encourages him to contact Gregory. Tommy strikes a deal with Gregory and gives him money to book a recording studio, but he soon learns he’s been scammed. Tommy takes his anger out on Mia and repeats that he’s not her father – he and Lacy never even had sex. Mia runs off. Deciding to hop on another train, she takes a picture of herself by the train-yard and sends it to Tommy. She jumps onto the train, only to find Tommy suddenly driving alongside. She leaps off the train and back into the car.

The two encounter Khalid, an urban hustler selling CDs who claims to be a producer. Listening to his music, Mia notices he has talent. Once again, she convinces her father to take a shot. It doesn’t go well at first – Khalid and his gang of aides pull a gun on them, but this turns out to be an “initiation” and eventually, they begin laying down tracks. The songs are by both Tommy and Mia under the name “The Piranhas”. Khalid offers to cut a whole album and Tommy and Mia spend days hustling to earn the cash. At last, the album is done and Khalid surprises them by giving them back their money.

Mia posts a video of their song online and it goes viral. A producer from the South by Southwest Music Festival contacts them about booking a gig. At Pacific Park, Mia is approached by Billy, a boy from school, and his friends. The boys flirt with her and then begin to bully her. When Tommy interferes, a boy coldcocks him with his skateboard. Tommy is hospitalized and now in a coma. Kate appears and lets Mia hear a song Tommy recorded for Kate called “Mia Culpa”. Khalid convinces Mia to go play the South by Southwest gig by herself. She does and performs “Mia Culpa” to great acclaim. She returns to Los Angeles where she continues to sit vigil for Tommy. As she sings to him, his fingers suddenly tap out a beat on her hand.