One day, there was a boy at the beach.
Suddenly he finds a mermaid in the water. He takes the mermaid to his house to show his parents but they couldn't see her because it was just the boys imagination.
In the country were the boy lived, no one was allowed to imagine as they pleased.
So the government tried many ways to stop the boy from imagining. Although the boy was tough, finally he wasn't able to see the mermaid anymore.
With a sad feeling, the boy went to the beach once more and saw the mermaid again.
The boy jumped in to the water, became a mermaid himself and went to a place together where no one could interfere them.
I think Osamu was trying to criticise governments that didn't allow people to make decisions on their own.
