The film tells the story of a twelve-year-old boy Kong (starred by Sit Lap Yin). Kong became melancholy since his biological mother took her own life some times ago; this psychic of his certainly has a dampening effect on his growth, especially on his height. He blames this on his father (starred by Felix Wong) and his stepmother (starred by Karen Mok) and dislikes the new family. The only one thing he looks forward to is to grow up quickly, leave his parents and become independent. One day, when he is wandering in the park, he meets with this tramp (starred by Feng Xiao Gang), who claims that he has invented a magic tonic to speed up growth. Kong somehow made accidental contact with the tonic and it turns him into the look of a twenty-year-old overnight. The "grown-up" Kong looks mature physically but is still a kid at his heart, this puts him under quite a few silly situations. Kong also decides to go after his dream girl and teacher (starred by Cherrie Yang) and the two actually goes well. It is out of anyone's expectation that time seems to have a much larger effect on Kong than to others; with the past of every night, Kong ages immensely. The fact is of course very disturbing to someone just fallen in love. On top of that, he also discovers the truth on his mother's suicide. Kong ends up racing with time to find his cure on one hand and try all means to right things wrong with his parents in order to resume to normal family life.
