Mary-Kate and Ashley learn a little more about life, love and ice cream floats in this great Sweet Sixteen story. Mary-Kate has stars in her eyes! She's just spent a week on a film set with friends Tyler (who's really cute!) and Danielle and her Mum, Diana, who just happens to be a famous actress. Mary-Kate comes back with a new name - Mikki - and a whole new attitude. No more ice cream floats, it's got to be sparkling mineral water; and when it comes to shopping, only the very best will do! Meanwhile, Ashley is trying to get together a play starring a bunch of four-year-olds; Mary-Kate thinks she knows best and muscles in on the lighting, the scriptwriting and the directing and annoys everyone so much, they threaten to pull out! Mary-Kate is left alone with a bunch of little kids to direct, and finds out just what hard work Ashley put in on the play. But then Tyler turns up. Mary-Kate decides to tell him the truth about everything, including her love of ice cream floats and he likes her even more! Together they pull the play together, and 'Mikki 'decides that being plain old Mary-Kate is fabulous enough for her.