Pippy-chan 

Tezuka’s undersea adventure, Pippy (1951-53) was originally serialized in Shuiesha’s Funny Book from December 1951 to May 1953, with a one-off Pippy side-story, “Pippy’s Adventure”, appearing in an Funny Book “Special Issue” in August 1952. With human overpopulation quickly becoming an immense problem, Dr. Lehman decides the best idea is for humanity to live in the sea. After his idea is ridiculed, he decides to experiment on his newborn son, turning him into the world’s first mer-person. However, believing his son has died as a result of the experiment, Dr. Lehman and his wife commit his body to the sea, just as an angry mob – complete with pick axes and lawn rakes – shows up on their doorstep, demanding to know where the child is. The pair is convicted of murder and sentenced to prison.