Main characters: the boy and the fish
Summary: The boy imagines a fish as a mermaid, and freely expresses his belief to others who do not share his point of view and criticize him for not following through with common sense.
The ending: I think that the boy chooses to follow his belief and the only way to keep it he must leave those who do not accept his way of thinking. Therefore, he drowns himself in the sea.
The message: People tend to follow only common sense, that they shut out others imagination and creativity. We should open our minds to new ways of thinking.