Anime: Jibaku-kun: Twelve World Story

Spaak, a very powerful and respected G.C. (Great Child) offers his position to a young boy named Bucky who has the dream to become the ruler of the world. In order to become a true G.C. to protect his land from animals that have gone haywire, he must cross the twelve countries and defeat each G.C. guardian who are ordered by the G.C. leader Hail to stop him. Kai and Pinky who are also G.C. follow Bucky on his journey to make his dream come true.

Source: ANN