Ellie Allard, a fully fledged teenager who's never been kissed, wakes up to her first day of Year 9, the year people's lives change for good. Already late for school, her day worsens still when her best friends Nadine and Magda return from the summer break and tell her they both have boyfriends. Desperate not to be the odd one out Ellie invents her own boyfriend hoping nobody will call her bluff. At home, Ellie's dad tells her that he wants his girlfriend Anna to move in with them.
There is going to be a party at Pete's house. Everyone is going but Ellie needs to convince her dad it'll be okay. All is not well at home as Anna moves in. Knowing her dad will probably say no to the party Ellie asks Anna - Anna says 'yes' so long as she stops playing the 'how far can I push Anna game'. Nadine's relationship with Liam intensifies and in need of advice she confides in Ellie. Feeling unqualified to deal with Nadine's dilemma Ellie turns to Magda. At the party Ellie gets her first kiss from Dan.
Recent events have made Ellie paranoid, she feels she looks too young. After the incident at the house party, Liam seeks to make amends with Nadine and invites her to 7th Heaven, a nightclub for over 18's. Pouncing on this invitation and much to Ellie's dread, Magda makes it a group outing for the girls. Ellie's home life isn't too good either as her pent up resentment of Anna finally boils over.
Ellie is left speechless when Dad and Anna announce that they are planning to marry but her main priority is to find a date to take to the wedding - Dan seems the obvious choice. Meanwhile, Nadine is trying to pluck up the courage to dump boyfriend Liam. Magda offers to set an example by dropping Greg - until it looks like he's beaten her to it.
Ellie and her dad have both got a case of wedding day nerves. While Anna's head is turned, Dad disappears. It's down to Ellie to sort things out before disaster strikes and the day is spoiled. But the wedding does finally take place and when Dan shows up, Ellie gets to enjoy some romance of her own.
Dan and Ellie have spent the whole of half term together as a couple, so why isn't she feeling fantastic? They've had fun but there's just something missing. Magda insists that Dan just needs to be moulded into a more attractive model, but Ellie's efforts to change his image fail miserably. Nadine has a much simpler solution - if there's a 'ping' when they kiss then it's meant to be. The chemistry just isn't there and Ellie has to finish it. But before she has time to think about her loss, Dad and Anna reveal shocking news of a brand new addition to the family.
Ellie has decided to think positively and concentrate on looking after pregnant Anna - whether she likes it or not. Magda decides Ellie needs something to keep her occupied until the baby is born - like a new boyfriend - and she has glimpsed just the person - a new boy who has just started work in the pet shop. After Magda arranges a field trip to the pet shop all the girls fancy him and Ellie realises she is going to have compete against Magda and Nadine to win his affections! However, the plan backfires when Ellie is about to ask him out and realises he isn't into girls at all.
Ellie discovers that Dan has a new girlfriend - even worse she is stick thin! Ellie suddenly feels fat and unattractive. Magda suggests a trip to the swimming pool and while Ellie gets some exercise, Magda gets chatting to a hunk called Mick. Meanwhile, Nadine is delighted to hear that she is a finalist in a pop video competiton.
Magda, Ellie and Nadine are officially depressed. Ellie makes it her mission to cheer her friends up with a day at the spa, but they decide revenge is the best medicine. Magda decides to steal Mick's clothes at the swimming pool, Nadine humiliates her nasty sister and Ellie deals with Dan's new girlfriend Zoe.
Greg announces his undying love for Magda, and as Nadine has received a love letter from a secret admirer, Ellie is the only singleton once again. But then she meets Russell at the shopping mall and it seems her luck is about to change. But the path to true love never runs smooth.
Ellie is officially in love - it's magical, wonderful and all consuming. Unfortunately, all her friends and family are being neglected as a result. Magda and Nadine are horrified at this selfish Ellie-Monster who only has eyes for Russell. They have given up on her and it's not until Anna is rushed to hospital that Ellie recoils at her bad behaviour. But is it too late to rectify?
Ellie can't resist sneaking a peek at Russell's sketchbook and is shocked to see that he's secretly read her diary. Meanwhile, Magda falls for art teacher Mr Green and pulls out all the stops to catch his eye. But all she gets is a big dose of embarrassment.
Life seems pretty perfect for Ellie until a concert with the girls clashes with Russell's school dance. She knows it would be sensible to tell the truth, but sometimes lies just spill out without warning. When Russell discovers the real reason why Ellie can't join him on the dance floor, he's less than impressed. It seems nothing can redeem Ellie's night until a frantic call from Dad puts a smile back on everyone's face.