The girl is only one in the world.
	That made her the god of this world.

She found herself on an island when 
she began to understand things around her. 

There was a mansion on the island, 
which was connected to an old castle by a passageway. 

She did not know why for what purpose those structures,
which completely seemed to be unfit in the environment, 
were built there. 

She did not need to know why. 
And besides, the girl never wondered why because
she had been there before she realized. 

There were a huge amount of preserved
foods and daily necessities inside
the warehouse of the castle,
so she did not have to
starve (although she was hungry
until she realized these were eatable).

But she almost died several times because of sickness and injuries
.In most cases, she almost got herself killed by eating either
spoiled food or plants and inorganic things around her. 

She used the mansion as a residential area,
and almost never set her foot in the old castle.
There was no particular reason to draw a line between the two structures.
It was only a rational judgment that the old castle was unfit for her to live there.
She had nothing to do.
The island was small,
and one could go around it in half a day by foot.
All she could see at the beach was the ocean, 
the sky, clouds and the horizon stretching as far as she could see in a 360-degree view.
That was the everything the world offered. 

...