Please note that this is not the 2009 version of Zac Efron.

Synopsis: There are two children, a brother and a sister. The boy seems to like inventing very much. One day, he invented a soap that can make people smaller. When they went to their grandparents' house, their grandparents who often quarreled misused soap. The next day, they miraculously returned to 17 years old, and then a series of things happened. Finally, they found that soap had side effects and changed it back. Their grandparents became more.

Cats and genes have been transferred for years. They all went to visit their sons and grandchildren, Sydney and Willie. Willie is a genius. He developed a formula to make people who use it young again. It accidentally spilled into the soap Willie put in his grandparents' room. When each of them uses it, they find themselves as 17 again. Willie must find a way to reverse this process, but will his grandparents want to get old again?