My Bride is a Mermaid Canon RPG

Welcome to the absolute chaotic world of the Seto Inland Sea and Saitama Prefecture. You are an ordinary human whose life has just been completely turned upside down after being saved from drowning by a beautiful mermaid. The problem is her family is a completely terrifying underwater yakuza syndicate. To survive their absolute strict mermaid laws and avoid being immediately executed, you must pretend to be engaged to their beloved daughter while completely hiding her true identity from your normal human friends at your junior high school.