아무도 우리에게 엄마와 같은 사람이 될 순 없어.

아무도. 절대 누구도 안돼.
특히 멍청하고 바보 같은 Rose아줌마는 절대 안돼!!!

Ruby와 Garnet은 이제 열 살이 된 쌍둥이 자매입니다.
둘은 언제나 모든 일들을 함께 해왔지만 특히 삼년 전 쌍둥이의 엄마가 돌아가시고부터 더욱더 붙어 다니기 시작했습니다.
자매는 옷도 똑같이 입고 머리모양도 똑같이 하고 수업도 언제나 함께 듣습니다.
하지만 둘이서 언제까지나 이렇게 함께하는 것이 가능할까요?
그들을 둘러싼 일상들에 점점 더 많은 변화들이 생기기 시작합니다.
아빠에게 여자친구가 생기고 게다가 새로운 지역으로 이사까지 가게 됩니다.

두 자매는 이 난관을 슬기롭게 헤쳐갈 수 있을까요?

Ten-year-old Ruby and Garnet are identical twins who do everything together. Especially since their mother died three years earlier. They dress alike, wear their hair the same, and sit together in every class. In fact, everything about them is the same--except their personalities. Ruby is funny and outgoing, Garnet is sensitive and shy. Together they're the perfect double act--and that's just the way they like it.
Soon the twins' life is turned upside down. Their dad has been spending a lot of time with his new "friend" Rose. Ruby and Garnet can't stand Rose. To make matters worse, Dad and Rose buy a bookstore out in the country and the whole family moves. Ruby hates their new school, but Garnet thinks it isn't all that bad. When Garnet befriends some of their new classmates, Ruby feels betrayed and stops speaking to Garnet. Garnet misses her sister terribly, but has to admit it's nice doing things on her own for a change. Somehow, the girls will have to find a way to maintain their special twin relationship without spending every minute of the day together.