Once Were Warriors

Beth left her small town and, despite her parents' disapproval, married Jake "the Muss" Heke. After 18 years they live in an unkempt state house in an unnamed New Zealand city and have five children. Their interpretations of life and being MÄori are tested. Their eldest daughter, Grace, keeps a journal in which she chronicles events as well as stories she tells her younger siblings.
Jake is fired from his job and is satisfied with receiving unemployment benefit, spending most days getting drunk at the local pub with his friends, singing songs, and savagely beating any patron he considers to have stepped out of line. He often invites crowds of friends from the bar to his home for drunken parties. When his wife "gets lippy" at one of his parties, he brutally attacks her in front of their friends. Beth turns to drink when things go wrong, and has angry outbursts and occasional violence of her own, on a much smaller scale. Her children fend for themselves, resignedly cleaning the blood-streaked house after their father has beat their mother.
Nig, the Hekes' eldest son, moves out to join a gang whose rituals include getting facial tattoos (in MÄori culture called tÄ moko). He is subjected to an initiation beating by the gang members but is then embraced as a new brother, and he later sports the gangâs tattoos. Nig cares about his siblings but despises his father. He is angered when his mother is beaten but deals with it by walking away.
The second son, Mark "Boogie" Heke, has a history of minor criminal offences; he is taken from his family and placed in a foster home as a ward of the state due to his parents' home life. Despite his initial anger, Boogie finds a new niche for himself, as the foster homeâs manager Mr. Bennett helps him embrace his MÄori heritage. Jake does not care that Boogie was taken away; he comments that it will do him some good, toughen him up a bit. Beth is heartbroken and scrapes money together to visit him. Jake pays for the rental car from gambling winnings but deserts the family to go to the pub, and they never make the journey.
Grace, the Hekes' 13-year-old daughter, loves writing stories. Her best friend is a homeless boy named Toot, who lives in a wrecked car. She despises the future she believes is inevitable and is constantly reminded of getting married and playing the role of a wife, which she believes comprises catering to oneâs husbandâs demands and taking beatings. She dreams of leaving, and being independent and single.
Grace is raped in her bed by her fatherâs friend "Uncle Bully", who tells her it is her fault for "turning him on" by wearing her "skimpy little nighty". She becomes depressed and seeks support from her friend Toot, with whom she smokes marijuana for the first time. Toot kisses her, but she reacts violently and storms out, believing he is "just like the rest of them". After wandering through the city streets, Grace comes home to an angry Jake with his friends. Bully asks for a goodnight kiss in front of everyone, to test his power over her. Grace refuses, and her father tears her journal in two and nearly beats her up. She runs out to the backyard crying. Beth returns home from searching for Grace, only to find that she has hanged herself from a tree branch in the backyard.
Jake stays in the pub with his mates, while the rest of the family takes Grace's body to a tangihanga. Beth stands up to him properly for the first time as he refuses to let her be taken to the marae. The film cuts back and forth between the mourning, Jake in the pub bottling it up, and the family on the marae. Boogie impresses Beth with his MÄori singing at the funeral, and Toot says his goodbyes, telling Grace the gentle kiss was all his gesture meant. Boogie reassures Toot that Grace loved him, and Beth invites Toot to live with them.
Reading Graceâs diary later that day, Beth finds out about the rape and confronts Bully in the pub. Jake at first threatens Beth, but Nig steps between them, protecting his mother. He hands his father Graceâs diary, and Jake reacts by severely beating Bully and stabbing him in the crotch with a glass bottle. Beth blames Jake just as much as Bully, so she leaves and states her intention to take their children back to her MÄori village and traditions, defiantly telling Jake that her MÄori heritage gives her the strength to resist his control over her. Jake hopelessly sits on a curb outside the pub as the family leaves, with sirens wailing in the background.

Question: Who is Uncle Billy?
Answer: A friend of Grace's father.