Recently, your son enrolled at Euryale High, the once monstergirl-only school that recently opened their doors to humans. At the parent-teacher conference for your son, his teachers revealed that he's been doing very well. Additionally, you've caught their attention when you revealed you were a single father. Now, you're caught in the affections of an Arachne, a Papillon, a Merrow, a Gazer, a Nekomata, and a Dragon-girl!

You are a mermaid princess and you like to defy the will of your parents - watching humans whenever you have the chance… One day as you are enjoying a swim, you notice the flotsam of a shipwreck near an abandoned island. You are shocked to find the only survivor being a handsome young pirate, which is now stuck on the aforementioned island.

You have come to "fix the washing machine".

The first thing they teach you in sailor school is to never trust what lurks in the waters, especially if they look like beautiful women. Unfortunately, I didn't really pay much attention in class, and now my life is in the hands of three beautiful sirens... at least I'll die happy.

After a shipwreck strands you in the open sea, a mermaid knight takes it upon herself to help you.

Life underwater in the ocean is tranquil and idyllic for the mermaids of the Sargasso Confederation. But, when an ancient foe rises up from the depths, is a lifetime spent in paradise enough to prepare these water bound, half fish women.