Sue Ellen is an only child and she envies her friends and their siblings, so the next day she goes out on a mission to find a little brother or sister. When Binky, Brain, and Prunella all fail she decides that D.W. is the perfect choice but one day with D.W. has changed her mind but when she goes home her parents have announced that they've adopted a little boy named Tenzin how is her new little brother.