Wang, 7, is so little for his age that his schoolmates tease him relentlessly. One day, tricked by his “friends”, he falls into a river and is swept away. At last, his sister Ping finds him. As he lies in bed with a fever, she slips her lucky dragon charm around his neck…

That night, the dragon comes to life and swells to a colossal size. Entering its mouth - a vast cave - Wang finds three huge, animated Buddhist statues tormented by a tiny monster. The small, agile boy catches the pest. To thank him, the statues grant his wish and make him big… too big! Having learnt his lesson, he asks to be returned to his original size.

Back in the everyday world, a little panda the children love is caught in a trap. Only Wang is brave and small enough to slip inside and free it. Now all his playmates admire him and the teasing stops.