Mermaid♡Prince

Synopsis

Masami, who's broke, is visited by some suspicious men who tell him that, thanks to his genes, he has a high chance of being able to reproduce with a critically endangered mermaid(♂), and if he's successful, they'll pay him 100 million yen. Bewildered, Masami is tempted by the 100 million yen, but... (Source: Shinshokan, translated)