It's summer in Boonelg, and just before school starts back, the hunk of Jennie's grade, Nick Lazzarri, returns from a juvenile detention facility. Jennie has always had a huge crush on Nick and decides that, as her last year at Boonelg High, this is the year she has to become more cool and make a move. She dyes her fringe blonde and buys a whole bain-marie of mini pizzas for Nick from the school canteen, but she is no match for the school's head skank, Tracy Hooker. Meanwhile, Jennie's Aunty Cassandra reunites with her sister Berenice after not speaking for three months. Berenice suspects something is up and is proved right when she discovers that Cassandra's husband Gary has left her to work on a gay cruise ship.

Jennie's mother, Berenice, has been chair-bound for weeks after a nasty spider bit her leg, but the doctor assesses that her main problem is her morbid obesity. Cassandra however, is more concerned with the well-being of her new cat Chinnie and exploiting the special needs adults she is supposed to be caring for. Jennie tries to help her mother lose weight, but after the Tummy Tumbler proves ineffective, she and her friends enlist the help of their GLS (God's Love Society) spiritual leaders, Miss La Mont and Miss Butcher, and they hold a cult-like intervention.

For Jennie and her best friends, Amy Lee and Nigella, the Maths Olympiad is the highlight of their academic calendar, but when it seems that Amy Lee has found a boyfriend on an opposing team, Jennie becomes jealous and the girls' competitive natures are unleashed. Meanwhile, Cassandra buries her cat Chinnie and then takes her charges to the cinema in the up-market nearby suburb, Spooner Hill. When Cassandra is refused free refills at the candy bar she is involved in an altercation with staff and is arrested.

Jennie needs to raise $10,000 for her mother's stomach stapling operation. Cassandra starts a Bonsai Cats franchise and ropes Jennie into selling them for her.

Jennie begins rehearsals for the with 'mega mad dance skills' to join their squad so that they may have a hope of beating the school skanks. Cassandra is sacked from her position as a professional carer due to her negligence but then discovers that one of her charges, Marilyn, has won a colouring-in competition but now can't collect the prize.

Cassandra uses Jennie as a 'replacement mong' in order to collect the prize for the colouring-in competition. Jennie enlists Nick into her dance battle team.