All the experiments and torture that made the boy in last half not to be able to see the fish as a mermaid was really shocking to me. I understand that long time ago was a era were people had to obey all kinds of rules that even includes our free will, but so long as you keep it inside your mind, no one will know. So, there is no way in stopping us humans to think and imagine whatever we want. Maybe that was the moral to this story that Tezuka wanted to tell us.
There is a comic called "Calvin and Hobbes " that also includes lots of imagination. Please try it, it's really funny and I recommend it.
