The main characters of this story are a boy and a fish which turns into a mermaid.
It takes place in a country which does not allow people to be imaginary. The problem is that people in the country does not believe the boy's statement that a fish turned into a mermaid. While the boy can see the fish as a mermaid, the people see them just a fish. The boy keeps claiming that "the fish isn't a fish, it is a mermaid." However, the people thought he is insane, so they put them in kind of a jail and force him to believe that the mermaid is just a fish. But until the end he did not believe that the mermaid is just a fish. He runs away from those people and finally himself becomes a mermaid. In the end, the two mermaid went into the ocean together.
The theme of this story is that the the terrifying controlled society.
