The basic summary is a boy with a big imagination that could see a mermaid wants to show it to his parents. His parents do not see the mermaid and thinks he's insane and send him to a mental institution. He goes through several experiments and gradually starts forgetting about the mermaid. Not wanting to forget he went back to the first place he met the mermaid and he saw the mermaid as well as everyone else who were on the beach.
There is a boy and a mermaid, the boy's parents and the police.
The setting was a long long time ago in a far far place.
The boy wants the people to understand that he can see a mermaid, but the countries law forbids imagination.
The mermaid is in the boys imagination but the boy thinks it's real.
In the end the boy could see his imaginative mermaid which he almost lost sight of and so could everyone else.
The people will probably apologize to the boy for experimenting on him when the problem was the lack of their own imagination and change the law.
The theme is never lose your imagination no matter what everyone else may say or do to you.
