The character was a boy and a mermaid.
At first a boy was looking into the water. He found a fish and suddenly the fish became a mermaid. The boy and the mermaid had a great time together so the boy decided to bring the mermaid home. He put the mermaid into a sink full of water. But this is when we found out that the boy is the only one who can see the mermaid as a mermaid. The rest of the people sees the mermaid as a fish. When the boy treats the fish as mermaid, people starts to think the boy got crazy. Since everyone thinks the boy is crazy, the police captures the boy.
At last, when the boy gets free from the police, he meets the mermaid again. He becomes a mermaid in the end.
In my opinion, the last part, when the boy becomes a mermaid and swims away with the mermaid, he was not swimming with the mermaid, it was only a fish.
This video was really mysterious. Although this video was really old, it was a good video.