The king of the Kaibutsu or Monster Kingdom thrust his son, young prince Taro, into the human world. Prince Taro, also known as Kaibutsu-kun must live among people for a while as part of a grooming process before taking over the kingdom. So begins the sometimes scary, sometimes touching and often very funny adventures of Kaibutsu-kun and his three affable attendants Dracula, Wolfman and Franken. The monsters meet humans Hiroshi and his older sister Utako, and through them, they learn about friendship, love, family and ultimately, the purpose of their mission: what it takes to be a leader.