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1. Echoes of the Sea by AoiUmi_97

   Fandoms: H2O: Just Add Water, Mako Mermaids, H2O: Mermaid Adventures (Cartoon)  

   • Not Rated
   • Creator Chose Not To Use Archive Warnings
   • F/F, F/M
   • Work in Progress

   13 May 2026

   Tags

   • Creator Chose Not To Use Archive Warnings
   • Inspired by H2O: Just Add Water
   • Moon Pool (H2O: Just Add Water)
   • Original Character(s)
   • Alternate Universe - Merpeople
   • Full Moon
   • Japan
   • Awkward Conversations
   • Transformation
   • Mermaids
   • Growing Closer by Shared Secrets
   • Singing
   • stage fright
   • Half-Filipino Character
   • unlikely friends
   • Ocean
   • Anime-Inspired
   • Anime Hair-Colors
   • Coming of Age

   Summary

   In the quiet seaside town of Aoshima, Japan, three high schoolers cross paths and get stranded on the remote island of Tsukishima. There, they encounter a mysterious Moon Pool at the center of a dormant volcano. Under the full moon, waves of glowing light ripple through the water, awakening ancient ocean magic. After escaping through the pool beneath the full moon, they discover the next morning that they now share a life-changing secret - whenever they touch water, they transform into mermaids. Now they must stick together while navigating life with this new secret.

   Language:

   English

   Words:

   8,752

   Chapters:

   3/?

   Comments:

   7

   Kudos:

   6

   Bookmarks:

   3

   Hits:

   181