The early stage tells the story of the growth of the five protagonists, and the later stage is the story of them traveling to other worlds to exercise (actually to find a partner)
There are hunters, gods of death, and tutors in the world they travel through. They will become one of the characters, and then they will be fixed in their image until they return to the original world.
This article is generally hilarious, if you don't like it, don't read it