Imaginary Tales from Other Worlds

There is more than one world.

One day, through a twist of fate, a young man makes a deal with the child of a god known as "the World" in legend: in exchange for the god's help, the boy will grant him roughly two wishes and take over his job.

But the job doesn't seem easy. It requires him to travel to different worlds.

From then on, the young man's already less-than-pleasant life becomes even less pleasant. He begins traveling to different worlds and eras.