I really have to wonder what managed to wipe out the population of mermaids before Mr. Qin broke out of his shell. They are already the top of the food chain yet his birth is definitely presented as if he was lost in the middle of a massive raid. Do the ones who caused it have anything to do with those overeager oncology doctors who kept calling the MC to come back for another exam?

Lets take a step back. Mr. Qin couldn’t have been the only mermaid who found treasures on the bottom of the ocean to sell to humans. How is the ocean floor not already cleaned of all it’s treasures???

Another step back... the mermaid’s reproductive ability is a bit too strong? I suspect that the main reason the population is low is due to their own carelessness. They casually forget anything from the courting period unless the relationship is confirmed. They discard the baby mermaids to any corner of the ocean to raise themselves. If Mr. Qin is anything to go by, the mermaids extinction must be caused by laziness... in everything but the bedroom.

Speaking of, the main couple may be able to completely restore the mermaid population by virtue of their own virility. I think they can easily produce 1-2 mermaids a year at minimum and they will likely live for a few hundred more years. If their children find human partners as well... the world’s ecology will soon change to a population of human-mermaid hybrids.

Switched babies and rich family drama. No redemption. That sort of thing.

Where's Grandpa Zhuang's reaction to MC having a kid? What about the little mermaid learning to change his tail to legs? And where's the reaction from everyone after MC declares his relationship with ML on TV? AHHHHHHH!!!!