Jimmy Johnson 5 years old has the body of a 2 year old, his 2 year old brother Timmy, has the body of a 5 year. Jimmy is supposed to start kindergarten but his mommy Patty knows he will be teased as he still has wetting accidents. Patty knows what to do, but does not know how Jimmy will take the news of her plan to have Jimmy take his brother's place and become Timmy Johnson.