Ella and Ari always knew they had a sister...they just didn't know it was each other.

When Ella and Ari start at St Hilda's secondary school, they both feel alone. But after a chance meeting at auditions for the choir, they become friends.

When they discover that not only are they both adopted, they're actually sisters, their worlds are turned upside down. While Ari is excited, Ella doesn't know how to respond, and the differences between Ari's laid-back dads and Ella's old-fashioned Mum only adds to the tension.

Then Ella's faced with the challenge of her Grandma's sudden illness, and when she leans on Ari in her time of need, the two families decide to try and make the relationship work, finding harmony together despite their differences.