There is a little boy nicknamed King Dirt, he is particularly sloppy and not hygienic, believe in "something which is not clean is safe to eat". One day, the Mouse King wanted to conquer mankind and dominate the world, so he wanted to find someone to test his bacterial weapon. And they trapped and tricked the little boy to the rat kingdom. In the rat kingdom, the King Dirt boy found himself jailed. He really regretted and wanted to go home, can he finally make it?